#51BBDF
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(74.4% 0.109 223.7), rgb(81, 187, 223).
Aa
Black text reads best on this color (9.52:1).
About this color
#51BBDF is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 74%, its chroma 0.109 and its hue 224°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.040 away. Black text reads best on it, at 9.52:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (74%) |
| Chroma | moderately saturated (0.109) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 9.52:1 |
| White text | 2.20:1 |
Values
| HEX | #51BBDF |
| RGB | rgb(81, 187, 223) |
| HSL | hsl(195, 69%, 60%) |
| OKLCH | oklch(74.4% 0.109 223.7) |
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 #51BBDF | 2.20:1 | Fails | Lc -47.9 | Large or bold text, headings |
| Black text on #51BBDF | 9.52:1 | AAA | Lc 60.8 | Content text, not long reading |
| #51BBDF text on white | 2.20:1 | Fails | Lc 43.1 | Non-text elements, placeholder text |
| #51BBDF text on black | 9.52:1 | AAA | Lc -59.0 | 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
#EFF7FA
oklch(97.1% 0.009 222.1)
-
Step 100
100
#DDEDF4
oklch(93.6% 0.019 225.7)
-
Step 200
200
#BFDFEC
oklch(88.4% 0.038 224.3)
-
Step 300
300
#90CBE1
oklch(80.9% 0.068 223.2)
-
Step 400
400 (this color)
#51BBDF
oklch(74.4% 0.109 223.7)
-
Step 500
500
#0098BE
oklch(63.1% 0.118 223.7)
-
Step 600
600
#0080A0
oklch(55.7% 0.104 223.4)
-
Step 700
700
#006B87
oklch(49% 0.092 224)
-
Step 800
800
#00586F
oklch(42.7% 0.08 223.4)
-
Step 900
900
#00495D
oklch(37.7% 0.071 223.8)
-
Step 950
950
#002B39
oklch(26.9% 0.051 225.5)
#51BBDF 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) | #A7B7E1 | 0.087 |
| Deuteranopia (no green cones) | #93A8DF | 0.077 |
| Tritanopia (no blue cones) | #00C6C7 | 0.061 |
| Achromatopsia (no color) | #AFAFAF | 0.110 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51BBDF
#51BBDF
oklch(74.4% 0.109 223.7)
- #E69573
#E69573
oklch(74.4% 0.109 43.4)
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 #51BBDF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.040
- Deep Sky Blue #00BFFF ΔE 0.049
- Bright Sky Blue #02CCFE ΔE 0.055
- Turquoise Blue #06B1C4 ΔE 0.058
- Lightblue #7BC8F6 ΔE 0.061
- Dark Turquoise #00CED1 ΔE 0.066
- Light Cornflower Blue #98C1D9 ΔE 0.072
- Sky #82CAFC ΔE 0.073
Use #51BBDF 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.