#51D4F9
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(81.3% 0.124 220.2), rgb(81, 212, 249).
Aa
Black text reads best on this color (12.13:1).
About this color
#51D4F9 is a light, moderately saturated teal or cyan. In OKLCH its lightness is 81%, its chroma 0.124 and its hue 220°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.031 away. Black text reads best on it, at 12.13:1.
| Hue family | Teals and cyans |
| Lightness | light (81%) |
| Chroma | moderately saturated (0.124) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 12.13:1 |
| White text | 1.73:1 |
Values
| HEX | #51D4F9 |
| RGB | rgb(81, 212, 249) |
| HSL | hsl(193, 93%, 65%) |
| OKLCH | oklch(81.3% 0.124 220.2) |
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 #51D4F9 | 1.73:1 | Fails | Lc -34.8 | Non-text elements, placeholder text |
| Black text on #51D4F9 | 12.13:1 | AAA | Lc 72.8 | Content text, not long reading |
| #51D4F9 text on white | 1.73:1 | Fails | Lc 31.0 | Non-text elements, placeholder text |
| #51D4F9 text on black | 12.13:1 | AAA | Lc -71.8 | 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
#EAF8FD
oklch(97% 0.016 221.1)
-
Step 100
100
#D1F0FB
oklch(93.6% 0.036 221.2)
-
Step 200
200
#A6E4F9
oklch(88.4% 0.069 220.9)
-
Step 300
300 (this color)
#51D4F9
oklch(81.3% 0.124 220.2)
-
Step 400
400
#00B2D8
oklch(70.7% 0.129 220.4)
-
Step 500
500
#0099B9
oklch(63.1% 0.115 219.7)
-
Step 600
600
#00809C
oklch(55.5% 0.101 220.3)
-
Step 700
700
#006C84
oklch(49.2% 0.09 220.2)
-
Step 800
800
#00586C
oklch(42.6% 0.078 220.2)
-
Step 900
900
#004A5B
oklch(37.8% 0.069 219.8)
-
Step 950
950
#002C37
oklch(27.1% 0.049 219.4)
#51D4F9 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) | #BDCFFB | 0.102 |
| Deuteranopia (no green cones) | #A6BDF9 | 0.093 |
| Tritanopia (no blue cones) | #00E0E0 | 0.061 |
| Achromatopsia (no color) | #C5C5C5 | 0.124 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51D4F9
#51D4F9
oklch(81.3% 0.124 220.2)
- #FFA98B
#FFA98B
oklch(81.2% 0.11 40)
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 #51D4F9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.031
- Bright Sky Blue #02CCFE ΔE 0.037
- Aqua Blue #02D8E9 ΔE 0.038
- Lightblue #7BC8F6 ΔE 0.041
- Sky Blue #87CEEB ΔE 0.043
- Light Sky Blue #87CEFA ΔE 0.043
- Sky #82CAFC ΔE 0.045
- Medium Turquoise #48D1CC ΔE 0.065
Use #51D4F9 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.