#EFFF51#EFFF51

#EFFF51 is a very light, vivid yellow. Relative luminance 0.905; OKLCH L 95.8% C 0.189 H 114.6°. Best body text is #000000 at 19.09:1 contrast (WCAG AA passes).

Color values

HEX	#EFFF51
RGB	rgb(239, 255, 81)
HSL	hsl(66, 100%, 66%)
HSV	hsv(66, 68%, 100%)
CMYK	cmyk(6.3%, 0%, 68.2%, 0%)
CIE-LAB	lab(96.19, -26.01, 77.13)
CIE-LCH	lch(96.19, 81.40, 108.63°)
OKLab	oklab(95.82% -0.0787 0.1723)
OKLCH	oklch(95.82% 0.189 114.6)
XYZ	xyz(72.8438, 90.4661, 21.4074)
Luminance	0.9046 (WCAG relative)
Temperature	warm
Family	yellow

Closest named colors

Perceptual scales

Shades

Tints

Tones

OKLCH scale

Color harmonies

complementary

#EFFF51 #6151FF

analogous

#FFB851 #EFFF51 #98FF51

triadic

#EFFF51 #51EFFF #FF51EF

tetradic

#EFFF51 #51FFB8 #6151FF #FF5198

square

#EFFF51 #51FFB8 #6151FF #FF5198

split-complementary

#EFFF51 #5198FF #B851FF

monochromatic

#C2D600 #E9FF14 #EFFF51 #F5FF8E #FAFFCB

Accessibility & contrast

On white

1.10

#EFFF51 on #FFFFFF

AA ✗AA large ✗AAA ✗

On black

19.09

#EFFF51 on #000000

AA ✓AA large ✓AAA ✓

Best text color

#000000 on #EFFF51

19.09:1 — WCAG AA (normal text) passes

Contrast matrix

fg \ bg	##EFFF51	#FFFFFF	#000000	##000000
##EFFF51	1.00	1.10	19.09	19.09
#FFFFFF	1.10	1.00	21.00	21.00
#000000	19.09	21.00	1.00	1.00
##000000	19.09	21.00	1.00	1.00

Color blindness preview

Protanopia (red-blind)

#FFF335

Deuteranopia (green-blind)

#FFF65E

Tritanopia (blue-blind)

#FEF0DD

Achromatopsia (no color)

#F4F4F4

Design tokens & code

CSS

--color: #efff51;
/* rgb */ color: rgb(239, 255, 81);
/* oklch */ color: oklch(95.8% 0.189 114.6);

Tailwind

colors: {
  custom: {
    50: '#f8ff8c',
    500: '#efff51',
    950: '#000000',
  },
}

SCSS

$custom: #efff51;
$custom-light: #f8ff8c;
$custom-dark: #000000;

JSON

{
  "hex": "#efff51",
  "rgb": {
    "r": 239,
    "g": 255,
    "b": 81
  },
  "hsl": {
    "h": 65.517,
    "s": 100,
    "l": 65.882
  },
  "oklch": {
    "l": 0.95822,
    "c": 0.18943,
    "h": 114.6
  },
  "luminance": 0.90465
}

Semantic roles & 50–950 ramp

primary

#EFFF51

secondary

#3425D0

accent

#00E615

background

#FFFFFC

surface

#FFFFF4

border

#D7D7CE

text

#18170D

muted

#86857F

Preview Lab

Preview with #EFFF51

Body copy rendered with the generated semantic roles for this colour.

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