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#b3c621

a balanced, vivid yellow · warm · closest name: Yellow Green

RGB
179, 198, 33
HSL
67°, 71%, 45%
CMYK
10, 0, 83, 22
Luminance
0.5008

At a glance

Every number on this page in one read: what #b3c621 is made of, how bright it looks, and which way it leans.

Hex
#b3c621
Hue
67°
yellow
Saturation
71%
vivid
Lightness
45%
balanced
Brightness
78%
HSV value
Perceived
71%
weighted brightness
Luminance
0.5008
WCAG relative
Temperature
Warm
31/100 cool
Color family
Yellow
Tone
Vivid
Best ink
Black
11.02:1
Closest name
Yellow Green
ΔE2000 6.4
Where it sits
Hue67° of 360°
Saturation71%
Lightness45%
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#b3c621
RGBrgb(179, 198, 33)
HSLhsl(67, 71%, 45%)
CMYKcmyk(10%, 0%, 83%, 22%)
LABlab(76.1 -25.3 71.5)
LCHlch(76.1 75.9 109.5)
OKLCHoklch(0.785 0.173 116.7)
Decimal11781665
Display P3color(display-p3 0.702 0.776 0.129)

Copy-ready code

/* CSS */
color: #b3c621;
background-color: #b3c621;
/* Tailwind (arbitrary) */
class="text-[#b3c621] bg-[#b3c621]"
/* SCSS */
$brand: #b3c621;
/* SwiftUI */
Color(red: 0.702, green: 0.776, blue: 0.129)
/* Android */
Color.parseColor("#b3c621")
/* Flutter */
Color(0xFFB3C621)
/* Python / OpenCV (BGR) */
(33, 198, 179)

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 #b3c621 · 11.02:1
Use #000000AAA at every size.
Aa
White text · 1.91:1
AA fail · AA large fail · AAA fail
Aa
Black text · 11.02:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #b3c621 as text scores 1.91:1 on white and 11.02:1 on black.

Accessibility — WCAG contrast

Aa
#b3c621 on white: 1.91:1
AA ✗ fail · AA-large · AAA
Aa
#b3c621 on black: 11.02:1
AA ✓ pass · AA-large · AAA
true color
protanopia · #D4BB00
deuteranopia · #D3BD33
tritanopia · #BFBAA9

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #b3c621 is pinned to step 600; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#FBFCF3
#F6F8E7
#EEF3C9
#E6EF9F
#D9E76F
#CCDF3F
#b3c621
#9EAF1D
#7E8C17
#5C6515
#3A3F0D
Base = 600Lightest = 50 · #FBFCF3Darkest = 950 · #3A3F0D
:root {
  --brand-50: #FBFCF3;
  --brand-100: #F6F8E7;
  --brand-200: #EEF3C9;
  --brand-300: #E6EF9F;
  --brand-400: #D9E76F;
  --brand-500: #CCDF3F;
  --brand-600: #b3c621;
  --brand-700: #9EAF1D;
  --brand-800: #7E8C17;
  --brand-900: #5C6515;
  --brand-950: #3A3F0D;
  --brand: #b3c621;
  --brand-ink: #000000;
}

Colors that work with #b3c621

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#929B4B
Captions on the surface
Accent#1C34CB
Second voice, not a rival
Dark variant#636D12
Hover, pressed, headers
Light variant#F9FBE9
Selected rows, tints
Dark surface#232414
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 #b3c621

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#3421C6
Analogous left#C68621
Analogous right#61C621
Split-complement 1#2161C6
Split-complement 2#8621C6
Triadic 1#21B3C6
Triadic 2#C621B3
Tetradic#21C686

RGB percentages

Red70.2%
Green77.6%
Blue12.9%

CMYK percentages

Cyan9.6%
Magenta0.0%
Yellow83.3%
Key (black)22.4%

Color previews

#b3c621 text on a black background

contrast 11.02:1

Card sample

#b3c621 text on a white background

contrast 1.91:1

Card sample

CSS3 live lab

Text font color

The quick brown fox

color: #b3c621;
Background color
Panel with #b3c621 background
background-color: #b3c621;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #b3c621;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(179, 198, 33, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(179, 198, 33, 0.45);
Border & gradient
Gradient panel
border: 3px solid #b3c621;
background: linear-gradient(135deg, #b3c621, #45C621);

Monochromatic scale

Palettes built from #b3c621

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.

#b3c621 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

Converts to four-color process without much drama. Proof it anyway.

#b3c621, answered

What color is #b3c621?

#b3c621 is a balanced vivid yellow, closest to Yellow Green (ΔE2000 6.4). It sits at 67° on the hue wheel with 71% saturation and 45% lightness, which reads as warm.

What is the RGB value of #b3c621?

rgb(179, 198, 33) — 179 red, 198 green and 33 blue out of 255, or 70.2% / 77.6% / 12.9% by channel.

Is #b3c621 a light or a dark color?

It is a light color. Relative luminance is 0.5008 and perceived brightness is 71%, so black text on it reaches 11.02:1.

Should I use black or white text on #b3c621?

Black. It scores 11.02:1 against #b3c621, versus 1.91:1 for white — AAA at any size.

What is the complementary color of #b3c621?

#3421C6 sits directly opposite on the wheel. Softer options are the split-complements #2161C6 and #8621C6, which give the same contrast with far less vibration.

What colors go well with #b3c621?

For interface work: #FAFAF4 as the surface, #E7EDC0 for borders, #929B4B for secondary text, #1C34CB as an accent and #636D12 for hover and pressed states. For a palette, the analogous pair #C68621 and #61C621 stays calm, while #3421C6 is the loudest partner.

What is #b3c621 in CMYK for printing?

cmyk(10%, 0%, 83%, 22%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #b3c621 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 #C69C21; nudged cooler, #77C81F.

Work with #b3c621 in the Color Lab