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#dff921

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

RGB
223, 249, 33
HSL
67°, 95%, 55%
CMYK
10, 0, 87, 2
Luminance
0.8355

At a glance

Every number on this page in one read: what #dff921 is made of, how bright it looks, and which way it leans.

Hex
#dff921
Hue
67°
yellow
Saturation
95%
electric
Lightness
55%
balanced
Brightness
98%
HSV value
Perceived
89%
weighted brightness
Luminance
0.8355
WCAG relative
Temperature
Warm
31/100 cool
Color family
Yellow
Tone
Electric
Best ink
Black
17.71:1
Closest name
Yellow
ΔE2000 5.9
Where it sits
Hue67° of 360°
Saturation95%
Lightness55%
Temperature
Warm ← → Cool31% cool

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

Every format

HEX#dff921
RGBrgb(223, 249, 33)
HSLhsl(67, 95%, 55%)
CMYKcmyk(10%, 0%, 87%, 2%)
LABlab(93.3 -31.4 87.0)
LCHlch(93.3 92.5 109.8)
OKLCHoklch(0.931 0.210 117.3)
Decimal14678305
Display P3color(display-p3 0.875 0.976 0.129)

Copy-ready code

/* CSS */
color: #dff921;
background-color: #dff921;
/* Tailwind (arbitrary) */
class="text-[#dff921] bg-[#dff921]"
/* SCSS */
$brand: #dff921;
/* SwiftUI */
Color(red: 0.875, green: 0.976, blue: 0.129)
/* Android */
Color.parseColor("#dff921")
/* Flutter */
Color(0xFFDFF921)
/* Python / OpenCV (BGR) */
(33, 249, 223)

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 #dff921 · 17.71:1
Use #000000AAA at every size.
Aa
White text · 1.19:1
AA fail · AA large fail · AAA fail
Aa
Black text · 17.71:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #dff921 as text scores 1.19:1 on white and 17.71:1 on black.

Accessibility — WCAG contrast

Aa
#dff921 on white: 1.19:1
AA ✗ fail · AA-large · AAA
Aa
#dff921 on black: 17.71:1
AA ✓ pass · AA-large · AAA
true color
protanopia · #FFEB00
deuteranopia · #FFED3D
tritanopia · #EEEAD5

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #dff921 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.

#FCFDF1
#F9FBE4
#F3FAC2
#EFFC92
#E7FB5B
#dff921
#D2EE06
#AFC705
#8C9F04
#667308
#404805
Base = 500Lightest = 50 · #FCFDF1Darkest = 950 · #404805
:root {
  --brand-50: #FCFDF1;
  --brand-100: #F9FBE4;
  --brand-200: #F3FAC2;
  --brand-300: #EFFC92;
  --brand-400: #E7FB5B;
  --brand-500: #dff921;
  --brand-600: #D2EE06;
  --brand-700: #AFC705;
  --brand-800: #8C9F04;
  --brand-900: #667308;
  --brand-950: #404805;
  --brand: #dff921;
  --brand-ink: #000000;
}

Colors that work with #dff921

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#E7EDC0
Hairlines and dividers
Muted text#919B4B
Captions on the surface
Accent#1D3AFE
Second voice, not a rival
Dark variant#6E7C03
Hover, pressed, headers
Light variant#FBFEE6
Selected rows, tints
Dark surface#222414
Dark-mode background
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

How to use #dff921

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
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

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#3B21F9
Analogous left#F9A721
Analogous right#73F921
Split-complement 1#2173F9
Split-complement 2#A721F9
Triadic 1#21DFF9
Triadic 2#F921DF
Tetradic#21F9A7

RGB percentages

Red87.5%
Green97.6%
Blue12.9%

CMYK percentages

Cyan10.4%
Magenta0.0%
Yellow86.7%
Key (black)2.4%

Color previews

#dff921 text on a black background

contrast 17.71:1

Card sample

#dff921 text on a white background

contrast 1.19:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #dff921;
Background color
Panel with #dff921 background
background-color: #dff921;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #dff921;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(223, 249, 33, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(223, 249, 33, 0.45);
Border & gradient
Gradient panel
border: 3px solid #dff921;
background: linear-gradient(135deg, #dff921, #4FF921);

Monochromatic scale

Palettes built from #dff921

Shades — darker

Tints — lighter

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.

#dff921 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.

#dff921, answered

What color is #dff921?

#dff921 is a balanced electric yellow, closest to Yellow (ΔE2000 5.9). It sits at 67° on the hue wheel with 95% saturation and 55% lightness, which reads as warm.

What is the RGB value of #dff921?

rgb(223, 249, 33) — 223 red, 249 green and 33 blue out of 255, or 87.5% / 97.6% / 12.9% by channel.

Is #dff921 a light or a dark color?

It is a light color. Relative luminance is 0.8355 and perceived brightness is 89%, so black text on it reaches 17.71:1.

Should I use black or white text on #dff921?

Black. It scores 17.71:1 against #dff921, versus 1.19:1 for white — AAA at any size.

What is the complementary color of #dff921?

#3B21F9 sits directly opposite on the wheel. Softer options are the split-complements #2173F9 and #A721F9, which give the same contrast with far less vibration.

What colors go well with #dff921?

For interface work: #FAFAF4 as the surface, #E7EDC0 for borders, #919B4B for secondary text, #1D3AFE as an accent and #6E7C03 for hover and pressed states. For a palette, the analogous pair #F9A721 and #73F921 stays calm, while #3B21F9 is the loudest partner.

What is #dff921 in CMYK for printing?

cmyk(10%, 0%, 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 #dff921 warm or cool?

Warm — it scores 31 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #F9C421; nudged cooler, #90FB1F.

Work with #dff921 in the Color Lab