#51BBD8
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(74.2% 0.105 218.8), rgb(81, 187, 216).
Aa
Black text reads best on this color (9.44:1).
About this color
#51BBD8 is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 74%, its chroma 0.105 and its hue 219°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.045 away. Black text reads best on it, at 9.44:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (74%) |
| Chroma | moderately saturated (0.105) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 9.44:1 |
| White text | 2.22:1 |
Values
| HEX | #51BBD8 |
| RGB | rgb(81, 187, 216) |
| HSL | hsl(193, 63%, 58%) |
| OKLCH | oklch(74.2% 0.105 218.8) |
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 #51BBD8 | 2.22:1 | Fails | Lc -48.3 | Large or bold text, headings |
| Black text on #51BBD8 | 9.44:1 | AAA | Lc 60.5 | Content text, not long reading |
| #51BBD8 text on white | 2.22:1 | Fails | Lc 43.5 | Non-text elements, placeholder text |
| #51BBD8 text on black | 9.44:1 | AAA | Lc -58.7 | Large or bold text, headings |
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 400.
-
Step 50
50
#EFF7F9
oklch(97.1% 0.009 214.3)
-
Step 100
100
#DDEDF2
oklch(93.6% 0.018 218.4)
-
Step 200
200
#C0DFEA
oklch(88.5% 0.036 221.2)
-
Step 300
300
#90CBDD
oklch(80.8% 0.066 218.8)
-
Step 400
400 (this color)
#51BBD8
oklch(74.2% 0.105 218.8)
-
Step 500
500
#0099B8
oklch(63.1% 0.114 219)
-
Step 600
600
#00819B
oklch(55.7% 0.1 218.5)
-
Step 700
700
#006C83
oklch(49.1% 0.089 219.3)
-
Step 800
800
#00596B
oklch(42.8% 0.077 217.7)
-
Step 900
900
#004A5A
oklch(37.8% 0.068 218.5)
-
Step 950
950
#002C36
oklch(27% 0.048 217.4)
#51BBD8 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) | #A9B6DA | 0.090 |
| Deuteranopia (no green cones) | #95A8D8 | 0.080 |
| Tritanopia (no blue cones) | #00C5C4 | 0.054 |
| Achromatopsia (no color) | #AEAEAE | 0.105 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51BBD8
#51BBD8
oklch(74.2% 0.105 218.8)
- #E4947A
#E4947A
oklch(74.1% 0.104 38.8)
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 #51BBD8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.045
- Turquoise Blue #06B1C4 ΔE 0.052
- Deep Sky Blue #00BFFF ΔE 0.058
- Dark Turquoise #00CED1 ΔE 0.061
- Bright Sky Blue #02CCFE ΔE 0.062
- Lightblue #7BC8F6 ΔE 0.066
- Medium Turquoise #48D1CC ΔE 0.070
- Topaz #13BBAF ΔE 0.071
Use #51BBD8 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.