#51C8EC
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(78% 0.117 221.4), rgb(81, 200, 236).
Aa
Black text reads best on this color (10.82:1).
About this color
#51C8EC is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 78%, its chroma 0.117 and its hue 221°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.006 away. Black text reads best on it, at 10.82:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (78%) |
| Chroma | moderately saturated (0.117) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 10.82:1 |
| White text | 1.94:1 |
Values
| HEX | #51C8EC |
| RGB | rgb(81, 200, 236) |
| HSL | hsl(194, 80%, 62%) |
| OKLCH | oklch(78% 0.117 221.4) |
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 #51C8EC | 1.94:1 | Fails | Lc -41.3 | Non-text elements, placeholder text |
| Black text on #51C8EC | 10.82:1 | AAA | Lc 67.0 | Content text, not long reading |
| #51C8EC text on white | 1.94:1 | Fails | Lc 36.9 | Non-text elements, placeholder text |
| #51C8EC text on black | 10.82:1 | AAA | Lc -65.5 | 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
#EBF8FD
oklch(97.1% 0.015 222.7)
-
Step 100
100
#D2F0FA
oklch(93.7% 0.034 219.8)
-
Step 200
200
#AAE4F8
oklch(88.6% 0.065 221.2)
-
Step 300
300 (this color)
#51C8EC
oklch(78% 0.117 221.4)
-
Step 400
400
#00B2DA
oklch(70.7% 0.13 221.5)
-
Step 500
500
#0098BB
oklch(63% 0.116 221.8)
-
Step 600
600
#00809E
oklch(55.6% 0.103 221.9)
-
Step 700
700
#006C85
oklch(49.2% 0.09 221.2)
-
Step 800
800
#00586D
oklch(42.6% 0.078 221.3)
-
Step 900
900
#00495C
oklch(37.6% 0.07 222.6)
-
Step 950
950
#002C38
oklch(27.2% 0.05 221.4)
#51C8EC 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) | #B3C3EE | 0.096 |
| Deuteranopia (no green cones) | #9DB3EC | 0.085 |
| Tritanopia (no blue cones) | #00D4D3 | 0.062 |
| Achromatopsia (no color) | #BABABA | 0.117 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51C8EC
#51C8EC
oklch(78% 0.117 221.4)
- #F79E7C
#F79E7C
oklch(78.1% 0.117 41.6)
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 #51C8EC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.006
- Bright Sky Blue #02CCFE ΔE 0.031
- Lightblue #7BC8F6 ΔE 0.038
- Aqua Blue #02D8E9 ΔE 0.049
- Sky #82CAFC ΔE 0.049
- Sky Blue #87CEEB ΔE 0.050
- Deep Sky Blue #00BFFF ΔE 0.050
- Light Sky Blue #87CEFA ΔE 0.054
Use #51C8EC 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.