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yellow · warm

#f9f521

a balanced, electric yellow · warm · closest name: Yellow

Token name suggestion: Studio Straw

RGB
249, 245, 33
HSL
59°, 95%, 55%
CMYK
0, 2, 87, 2
Luminance
0.8555

#f9f521 is a balanced electric yellow, 59° on the wheel and 24/100 on the cool side. Put black text on it (18.11:1). As text it scores 1.16:1 on white — use #797603 instead. Nearest name is Yellow, nearest Tailwind family is yellow.

hsl(59 95% 55%)rgb(249 245 33)Base step 500AAA inkWarm

At a glance

Every number on this page in one read: what #f9f521 is made of, how bright it looks, and which way it leans.

Hex
#f9f521
Hue
59°
yellow
Saturation
95%
electric
Lightness
55%
balanced
Brightness
98%
HSV value
Perceived
91%
weighted brightness
Luminance
0.8555
WCAG relative
Temperature
Warm
24/100 cool
Color family
Yellow
Tone
Electric
Best ink
Black
18.11:1
Closest name
Yellow
ΔE2000 2.3
Chroma
90.5
LCH, 0–130ish
OKLCH L
0.943
perceptual lightness
Tailwind
yellow
500 · ΔE 18.8
Web-safe
#FFFF33
nearest of 216
Where it sits
Hue59° of 360°
Saturation95%
Lightness55%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #f9f521.

Temperature
Warm ← → Cool24% cool

Reads warm. Warm and cool siblings keep the same lightness, so you can swap one in without redoing your contrast maths.

Luminance by channel
Red24%
Green76%
Blue0%

Green carries most of what the eye calls brightness — that is why WCAG weights it 0.7152.

Every format

HEX#f9f521
HEX (8-digit)#f9f521ff
RGBrgb(249, 245, 33)
RGBArgba(249, 245, 33, 1)
HSLhsl(59, 95%, 55%)
HSV / HSBhsv(59, 87%, 98%)
HWBhwb(59 13% 2%)
CMYKcmyk(0%, 2%, 87%, 2%)
LABlab(94.1 -18.9 88.5)
LCHlch(94.1 90.5 102.0)
OKLCHoklch(0.943 0.199 108.4)
XYZ (D65)xyz(72.00, 85.56, 14.16)
Decimal16381217
Display P3color(display-p3 0.976 0.961 0.129)
Web-safe#FFFF33

Copy-ready code

every platformclick to select
/* CSS */
color: #f9f521;
background-color: #f9f521;
/* CSS custom property */
--brand: #f9f521;
/* Tailwind (arbitrary) */
class="text-[#f9f521] bg-[#f9f521]"
/* SCSS */
$brand: #f9f521;
/* SwiftUI */
Color(red: 0.976, green: 0.961, blue: 0.129)
/* UIKit */
UIColor(red: 0.976, green: 0.961, blue: 0.129, alpha: 1)
/* Android XML */
<color name="brand">#F9F521</color>
/* Android Compose */
Color(0xFFF9F521)
/* Flutter */
Color(0xFFF9F521)
/* Python / OpenCV (BGR) */
(33, 245, 249)
/* Python / PIL (RGB) */
(249, 245, 33)
/* Java AWT */
new Color(249, 245, 33)
/* .NET */
Color.FromArgb(255, 249, 245, 33)
/* OpenGL / Unity (0–1) */
(0.9765f, 0.9608f, 0.1294f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{249,245,33}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #f9f521 85%, white);
border-color: color-mix(in oklab, #f9f521 40%, transparent);
/* theme-aware in one line */
color: light-dark(#7C7A03, #EEEED3);
/* relative colour syntax */
--hover: hsl(from #f9f521 h s calc(l - 7));

Design tokens

The same ramp in the four formats a team actually needs. Paste one and the whole palette lands with it.

css custom propertiesclick to select
:root {
  --brand-50: #FDFDF1;
  --brand-100: #FBFBE4;
  --brand-200: #FAF9C2;
  --brand-300: #FCFA92;
  --brand-400: #FBF85B;
  --brand-500: #f9f521;
  --brand-600: #EEEA06;
  --brand-700: #C7C305;
  --brand-800: #9F9C04;
  --brand-900: #737108;
  --brand-950: #484605;
  --brand: #f9f521;
  --brand-ink: #000000;
  --brand-surface: #FAFAF4;
  --brand-border: #EDECC0;
  --brand-hover: #F0EC07;
  --brand-pressed: #CDC906;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #242414;
    --brand-ink: #EEEED3;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#FDFDF1',
        100: '#FBFBE4',
        200: '#FAF9C2',
        300: '#FCFA92',
        400: '#FBF85B',
        500: '#f9f521',
        600: '#EEEA06',
        700: '#C7C305',
        800: '#9F9C04',
        900: '#737108',
        950: '#484605',
        DEFAULT: '#f9f521',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #FDFDF1,
  '100': #FBFBE4,
  '200': #FAF9C2,
  '300': #FCFA92,
  '400': #FBF85B,
  '500': #f9f521,
  '600': #EEEA06,
  '700': #C7C305,
  '800': #9F9C04,
  '900': #737108,
  '950': #484605,
);
$brand-base: #f9f521;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#FDFDF1", "$type": "color" },
      "100": { "$value": "#FBFBE4", "$type": "color" },
      "200": { "$value": "#FAF9C2", "$type": "color" },
      "300": { "$value": "#FCFA92", "$type": "color" },
      "400": { "$value": "#FBF85B", "$type": "color" },
      "500": { "$value": "#f9f521", "$type": "color" },
      "600": { "$value": "#EEEA06", "$type": "color" },
      "700": { "$value": "#C7C305", "$type": "color" },
      "800": { "$value": "#9F9C04", "$type": "color" },
      "900": { "$value": "#737108", "$type": "color" },
      "950": { "$value": "#484605", "$type": "color" }
    },
    "brandInk": { "$value": "#000000", "$type": "color" }
  }
}

Best text color

Only one of black and white can be right. This is the one, with the number that proves it.

Readable at a glance#000000 on #f9f521 · 18.11:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 1.16:1
AA fail · AA large fail · AAA fail
Aa
Black text · 18.11:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #f9f521 as text scores 1.16:1 on white and 18.11:1 on black.
Best tinted ink on it, if plain black or white feels flat: #7C7A03 at 3.90:1.

Make it accessible

A contrast checker tells you that you failed. This tells you what to ship instead — same hue, same saturation, lightness moved only as far as WCAG demands.

The quick fox
#797603 · 4.77:1
AA on white−31% L
#797603
The quick fox
#5B5902 · 7.31:1
AAA on white−37% L
#5B5902
The quick fox
#f9f521 · 18.11:1
AA on blackalready passes
#f9f521
The quick fox
#f9f521 · 18.11:1
AAA on blackalready passes
#f9f521

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #9B9904 is enough for headings on white. Non-text elements such as icons, chart strokes and focus rings also sit at 3:1 under WCAG 2.2 (1.4.11).

Accessibility — WCAG contrast

Aa
#f9f521 on white: 1.16:1
AA ✗ fail · AA-large · AAA
Aa
#f9f521 on black: 18.11:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #f9f521 as text on that neutral, and that neutral as text on #f9f521.

NeutralRatioBoth directions
White1.16:1AaAa
Slate 501.11:1AaAa
Slate 1001.06:1AaAa
Slate 2001.06:1AaAa
Slate 3001.28:1AaAa
Slate 4002.21:1AaAa
Slate 5004.10:1AaAa
Slate 6006.54:1AaAa
Slate 7008.93:1AaAa
Slate 80012.62:1AaAa
Slate 90015.40:1AaAa
Black18.11:1AaAa
Colour vision deficiency
true color
protanopia · #FFEB00
deuteranopia · #FFF13A
tritanopia · #FFE4D1

Roughly one man in twelve has some form of colour vision deficiency. If any of the three panels above is hard to tell apart from a neighbouring colour in your palette, add a shape, an icon or a label so the meaning does not rest on hue alone.

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #f9f521 is pinned to step 500; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#FDFDF1
#FBFBE4
#FAF9C2
#FCFA92
#FBF85B
#f9f521
#EEEA06
#C7C305
#9F9C04
#737108
#484605
Base = 500Lightest = 50 · #FDFDF1Darkest = 950 · #484605Text step on white = 900
Perceptual ramp — OKLCH

The same eleven steps expressed in OKLCH, where equal lightness numbers actually look equally spaced. HSL ramps go muddy in the yellows and washed out in the blues; this one does not. Modern browsers render it natively — the hex ramp above is the fallback.

50100200300400500600700800900950
oklch tokensclick to select
:root {
  --brand-50: oklch(0.97 0.050 108.4);
  --brand-100: oklch(0.94 0.079 108.4);
  --brand-200: oklch(0.88 0.119 108.4);
  --brand-300: oklch(0.80 0.155 108.4);
  --brand-400: oklch(0.72 0.183 108.4);
  --brand-500: oklch(0.64 0.199 108.4);
  --brand-600: oklch(0.56 0.199 108.4);
  --brand-700: oklch(0.48 0.187 108.4);
  --brand-800: oklch(0.40 0.167 108.4);
  --brand-900: oklch(0.32 0.139 108.4);
  --brand-950: oklch(0.24 0.109 108.4);
}

Colors that work with #f9f521

Not a palette — a role sheet. Each swatch answers one question you will hit while building the component.

Text on it#000000
Black wins here
Surface#FAFAF4
Tinted page background
Border#EDECC0
Hairlines and dividers
Muted text#9B994B
Captions on the surface
Accent#1D59FE
Second voice, not a rival
Dark variant#7C7A03
Hover, pressed, headers
Light variant#FEFEE6
Selected rows, tints
Dark surface#242414
Dark-mode background
Hover#F0EC07
One step down in lightness
Pressed#CDC906
Two steps down
Disabled#D2D1B8
Chroma pulled out
Focus ring#FFFB2F
Offset from the fill so it reads
Light mode
Everything in its place

Surface, border, heading and body all derive from this one hue, so the screen stays coherent without a second palette.

Primary actionSecondaryBadge
Dark mode
Same hue, inverted

Lightness flips, hue holds. The accent stays the anchor in both themes.

Primary actionSecondaryAccent

In real components

The same eight roles, wired into the interface patterns you will actually build with them. Every state below is a computed value, not a mock-up.

Buttons and states
Save changesHoverPressedDisabled
OutlineSubtleLinkFocused
Form field
you@company.com

Focus ring uses the light variant so the field still reads as one shape.

Send me product updates
Notice
Your export is ready

The file stays available for seven days. Download it before it expires.

NewBetaDraft
Data
Storage used68%
Acme LtdActive
NorthwindTrial
GlobexActive

How to use #f9f521

Derived from its contrast, chroma and lightness — not from taste.

Works well for
  • Text and icons on dark surfaces
  • Primary buttons and calls to action
  • Focus rings, active and selected states
  • Brand accents, badges and data highlights
  • Chart series and data categories
Use with care
  • Text of any size on white — fails WCAG AA
  • Full-page backgrounds — tiring over long sessions
  • Thin strokes and 1px borders — they disappear on light UI
  • Pairing with a same-lightness hue — edges vibrate
Minimum size as text on white
Not as text
Safe as a fill behind white type
No — use #7C7A03
Safe as a 1px border on white
No — use #9B9904

Meaning and mood

What a colour in this family tends to signal, and how this particular chroma and lightness change the reading.

optimisticalertcheap-and-cheerfulvisible

The most visible hue at low light levels, which is why it owns warnings, hazard tape and value retail.

At this chroma the association is amplified — it will dominate anything placed beside it, so give it space and use it sparingly. The mid lightness keeps it versatile in both themes.

Worth knowing

Almost never passes contrast against white. Treat it as a surface or a marker, not as text.

Reads as
  • FormalityLow
  • EnergyHigh
  • Weight45/100
  • TemperatureWarm
  • ApproachabilityHigh

Colour associations are cultural and vary by market. Treat these as a starting point for a conversation with your audience, not a finding about them.

Similar colors

One move away from this hex in each direction. Every swatch is its own page.

Color relationships

The wheel positions with their names attached, so you can grab the one you actually need.

Complementary#2125F9
Analogous left#F98921
Analogous right#91F921
Split-complement 1#2191F9
Split-complement 2#8921F9
Triadic 1#21F9F5
Triadic 2#F521F9
Tetradic#21F989
On the wheel
Base+30°−30°+120°+240°+180°59°

#f9f521 sits at 59°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red97.6%
Green96.1%
Blue12.9%
R · 0–255
249
0xf9
G · 0–255
245
0xf5
B · 0–255
33
0x21

CMYK percentages

Cyan0.0%
Magenta1.6%
Yellow86.7%
Key (black)2.4%

Total ink coverage is 91%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#f9f521 text on a black background

contrast 18.11:1

Card sample

#f9f521 text on a white background

contrast 1.16:1

Card sample

#f9f521 on grey

1.06:1

#f9f521 on its own surface

1.11:1

#f9f521 on its dark surface

13.54:1

CSS3 live lab

Text font color

The quick brown fox

color: #f9f521;
Background color
Panel with #f9f521 background
background-color: #f9f521;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #f9f521;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(249, 245, 33, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(249, 245, 33, 0.45);
Border & gradient
Gradient panel
border: 3px solid #f9f521;
background: linear-gradient(135deg, #f9f521, #6DF921);
Gradient text

Gradient headline

background: linear-gradient(90deg, #f9f521, #37F921);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #f9f521;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #f9f521;
caret-color: #f9f521;
Left rule
Pull quote or callout
border-left: 4px solid #f9f521;
Ring + tint
Selected chip
background: #FEFEE6;
box-shadow: inset 0 0 0 2px #f9f521;
Conic badge
68%
background: conic-gradient(#f9f521 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #f9f521 over white; the bottom row is the same alpha over a checkerboard, so you can see what survives on a photo or a video.

Bottom row of hexes is the flattened result over white — use those when a design tool refuses transparency, or when you need a solid fallback.

alpha in every syntaxclick to select
rgba(249, 245, 33, 0.5)
rgb(249 245 33 / 50%)
#f9f52180
hsl(59 95% 55% / 50%)
color-mix(in srgb, #f9f521 50%, transparent)
Alpha8-digit hexFlat on white
10%#f9f5211a#FEFEE9
20%#f9f52133#FEFDD3
40%#f9f52166#FDFBA6
60%#f9f52199#FBF97A
80%#f9f521cc#FAF74D

Gradients from #f9f521

Six recipes, each built from this hex and shown with the exact CSS that produced it.

Elevation
Same hue, three lightnesses — safe anywhere
background: linear-gradient(135deg, #FBF85D, #f9f521 45%, #7C7A03);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #f9f521, #47F507);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #f9f521, #2125F9);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #FBF97A 0%, #f9f521 45%, #7C7A03 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #FAFAF4, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #FA9553 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #90FA3F 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #7C7A03 0%, transparent 65%), #f9f521;

Monochromatic scale

Palettes built from #f9f521

Shades — darker

Tints — lighter

Tones — desaturated

Color harmonies

Nearest named colors

Ranked with CIEDE2000 across all 139 CSS keywords. Under ΔE 2 the eye stops telling them apart; over ΔE 10 they are plainly different colors.

#f9f521 in the real world

Where a color in this family tends to land, and the interface roles it is usually asked to play.

Industries
RetailLeisureEnergyWarning systems
Common UI roles
ButtonsLinksFocus statesCharts
Print note

Sits outside most CMYK gamuts — expect a duller press result, or specify a spot ink.

On screens

Very light values are indistinguishable from white on a dim phone screen outdoors. Give it a border if the boundary matters.

In dark mode

Usable as-is on a dark surface at 18.11:1.

Explore nearby colors

Small, deliberate steps away from this hex — useful when you are hunting for the version of a colour that finally feels right.

#f9f521, answered

What color is #f9f521?

#f9f521 is a balanced electric yellow, closest to Yellow (ΔE2000 2.3). It sits at 59° on the hue wheel with 95% saturation and 55% lightness, which reads as warm.

What is the RGB value of #f9f521?

rgb(249, 245, 33) — 249 red, 245 green and 33 blue out of 255, or 97.6% / 96.1% / 12.9% by channel.

What is #f9f521 in HSL and HSV?

hsl(59, 95%, 55%) and hsv(59, 87%, 98%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #f9f521 a light or a dark color?

It is a light color. Relative luminance is 0.8555 and perceived brightness is 91%, so black text on it reaches 18.11:1.

Should I use black or white text on #f9f521?

Black. It scores 18.11:1 against #f9f521, versus 1.16:1 for white — AAA at any size.

Is #f9f521 accessible on a white background?

#f9f521 on white scores 1.16:1, which fails WCAG AA at every size. Darken it to #797603 to reach 4.5:1, or #5B5902 for 7:1.

What is the complementary color of #f9f521?

#2125F9 sits directly opposite on the wheel. Softer options are the split-complements #2191F9 and #8921F9, which give the same contrast with far less vibration.

What colors go well with #f9f521?

For interface work: #FAFAF4 as the surface, #EDECC0 for borders, #9B994B for secondary text, #1D59FE as an accent and #7C7A03 for hover and pressed states. For a palette, the analogous pair #F98921 and #91F921 stays calm, while #2125F9 is the loudest partner.

What is #f9f521 in CMYK for printing?

cmyk(0%, 2%, 87%, 2%). This is a screen-to-ink approximation — a color this saturated sits outside most CMYK gamuts and will print duller than it looks here.

Is #f9f521 warm or cool?

Warm — it scores 24 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #F9B721; nudged cooler, #AEFB1F.

Which Tailwind color is closest to #f9f521?

The yellow family — its 500 step is #eab308, ΔE2000 18.8 away. That is a visible difference, so define #f9f521 as a custom token rather than reaching for the built-in.

How do I use #f9f521 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#f9f521] or text-[#f9f521], or register the whole ramp under theme.extend.colors.brand so you get bg-brand-500 and friends. The generated 50–950 scale on this page is ready to paste into your config.

What is #f9f521 with 50% opacity?

rgba(249, 245, 33, 0.5), or #f9f52180 in eight-digit hex. Over white that composites to #FCFA90; over black, #7D7B11.

Is #f9f521 a web-safe color?

No. The nearest web-safe colour is #FFFF33, ΔE2000 2.1 away. The palette only matters for legacy displays and some email clients now.

What does the color #f9f521 mean?

As a yellow, it reads optimistic, alert, cheap-and-cheerful. The most visible hue at low light levels, which is why it owns warnings, hazard tape and value retail. At this chroma the effect is amplified — it will dominate whatever sits beside it.

What gradient works with #f9f521?

The safest is same-hue elevation: linear-gradient(135deg, #FBF85D, #f9f521 45%, #7C7A03). For more colour, a short hue run to #47F507 keeps it rich without turning muddy.

Work with #f9f521 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #f9f521 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.