#51CDFE
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(79.9% 0.128 228), rgb(81, 205, 254).
Aa
Black text reads best on this color (11.51:1).
About this color
#51CDFE is a light, moderately saturated teal or cyan. In OKLCH its lightness is 80%, its chroma 0.128 and its hue 228°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.022 away. Black text reads best on it, at 11.51:1.
| Hue family | Teals and cyans |
| Lightness | light (80%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 11.51:1 |
| White text | 1.82:1 |
Values
| HEX | #51CDFE |
| RGB | rgb(81, 205, 254) |
| HSL | hsl(197, 99%, 66%) |
| OKLCH | oklch(79.9% 0.128 228) |
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 #51CDFE | 1.82:1 | Fails | Lc -37.8 | Non-text elements, placeholder text |
| Black text on #51CDFE | 11.51:1 | AAA | Lc 70.1 | Content text, not long reading |
| #51CDFE text on white | 1.82:1 | Fails | Lc 33.8 | Non-text elements, placeholder text |
| #51CDFE text on black | 11.51:1 | AAA | Lc -68.9 | Content text, not long reading |
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 300.
-
Step 50
50
#EAF8FF
oklch(97.1% 0.018 229)
-
Step 100
100
#D1EFFE
oklch(93.5% 0.037 229.3)
-
Step 200
200
#A8E3FF
oklch(88.5% 0.071 228.9)
-
Step 300
300 (this color)
#51CDFE
oklch(79.9% 0.128 228)
-
Step 400
400
#00B0E4
oklch(70.7% 0.138 228.2)
-
Step 500
500
#0097C4
oklch(63.2% 0.123 228.1)
-
Step 600
600
#007FA5
oklch(55.7% 0.108 227.8)
-
Step 700
700
#006A8B
oklch(49% 0.096 228.3)
-
Step 800
800
#005773
oklch(42.7% 0.084 228.5)
-
Step 900
900
#004960
oklch(37.8% 0.073 227.3)
-
Step 950
950
#002B3B
oklch(27% 0.053 228.8)
#51CDFE 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) | #B3CAFF | 0.092 |
| Deuteranopia (no green cones) | #9BB8FD | 0.081 |
| Tritanopia (no blue cones) | #00DBDD | 0.075 |
| Achromatopsia (no color) | #C0C0C0 | 0.129 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51CDFE
#51CDFE
oklch(79.9% 0.128 228)
- #FFA474
#FFA474
oklch(80% 0.125 48.1)
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 #51CDFE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.022
- Bright Sky Blue #02CCFE ΔE 0.025
- Lightblue #7BC8F6 ΔE 0.032
- Sky #82CAFC ΔE 0.038
- Light Sky Blue #87CEFA ΔE 0.044
- Sky Blue #87CEEB ΔE 0.049
- Deep Sky Blue #00BFFF ΔE 0.051
- Aqua Blue #02D8E9 ΔE 0.054
Use #51CDFE 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.