#51EEFF
Closest named color: Robin's Egg (#6DEDFD). oklch(87.5% 0.13 205.5), rgb(81, 238, 255).
Aa
Black text reads best on this color (15.02:1).
About this color
#51EEFF is a light, moderately saturated teal or cyan. In OKLCH its lightness is 87%, its chroma 0.130 and its hue 206°. Its hue sits on the cool side of the wheel. The nearest named color is Robin's Egg (#6DEDFD), ΔE 0.016 away. Black text reads best on it, at 15.02:1.
| Hue family | Teals and cyans |
| Lightness | light (87%) |
| Chroma | moderately saturated (0.130) |
| Temperature | cool |
| Nearest name | Robin's Egg (#6DEDFD) |
| Black text | 15.02:1 |
| White text | 1.39:1 |
Values
| HEX | #51EEFF |
| RGB | rgb(81, 238, 255) |
| HSL | hsl(186, 100%, 66%) |
| OKLCH | oklch(87.5% 0.13 205.5) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #51EEFF | 1.39:1 | Fails | Lc -21.6 | Dividers and decoration only |
| Black text on #51EEFF | 15.02:1 | AAA | Lc 84.8 | Fine for body text |
| #51EEFF text on white | 1.39:1 | Fails | Lc 18.9 | Dividers and decoration only |
| #51EEFF text on black | 15.02:1 | AAA | Lc -84.6 | Fine for body text |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 200.
-
Step 50
50
#E5FAFD
oklch(97.1% 0.022 207.1)
-
Step 100
100
#C5F4FA
oklch(93.6% 0.049 205.9)
-
Step 200
200 (this color)
#51EEFF
oklch(87.5% 0.13 205.5)
-
Step 300
300
#00D9EB
oklch(80.8% 0.138 205.4)
-
Step 400
400
#00B5C5
oklch(70.6% 0.121 206)
-
Step 500
500
#009CA9
oklch(63.2% 0.108 205.2)
-
Step 600
600
#00838E
oklch(55.7% 0.095 205.2)
-
Step 700
700
#006E78
oklch(49.1% 0.084 205.8)
-
Step 800
800
#005A62
oklch(42.7% 0.073 205.3)
-
Step 900
900
#004B52
oklch(37.7% 0.064 205.5)
-
Step 950
950
#002D31
oklch(27.1% 0.046 204.1)
#51EEFF with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #DBE5FF | 0.127 |
| Deuteranopia (no green cones) | #C2D2FF | 0.117 |
| Tritanopia (no blue cones) | #00F8F3 | 0.041 |
| Achromatopsia (no color) | #DADADA | 0.131 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51EEFF
#51EEFF
oklch(87.5% 0.13 205.5)
- #FFC6BF
#FFC6BF
oklch(87.5% 0.066 26.5)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #51EEFF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Robin's Egg #6DEDFD ΔE 0.016
- Bright Light Blue #26F7FD ΔE 0.028
- Robin Egg Blue #8AF1FE ΔE 0.041
- Bright Cyan #41FDFE ΔE 0.041
- Cyan #00FFFF ΔE 0.047
- Bright Turquoise #0FFEF9 ΔE 0.048
- Robin's Egg Blue #98EFF9 ΔE 0.052
- Bright Aqua #0BF9EA ΔE 0.052
Use #51EEFF in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.