#51BCDA
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(74.5% 0.106 219.4), rgb(81, 188, 218).
Aa
Black text reads best on this color (9.55:1).
About this color
#51BCDA is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 74%, its chroma 0.106 and its hue 219°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.041 away. Black text reads best on it, at 9.55:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (74%) |
| Chroma | moderately saturated (0.106) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 9.55:1 |
| White text | 2.19:1 |
Values
| HEX | #51BCDA |
| RGB | rgb(81, 188, 218) |
| HSL | hsl(193, 65%, 59%) |
| OKLCH | oklch(74.5% 0.106 219.4) |
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 #51BCDA | 2.19:1 | Fails | Lc -47.7 | Large or bold text, headings |
| Black text on #51BCDA | 9.55:1 | AAA | Lc 61.0 | Content text, not long reading |
| #51BCDA text on white | 2.19:1 | Fails | Lc 43.0 | Non-text elements, placeholder text |
| #51BCDA text on black | 9.55:1 | AAA | Lc -59.2 | 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
#DDEDF3
oklch(93.6% 0.019 222.2)
-
Step 200
200
#BFDFEA
oklch(88.4% 0.037 220.6)
-
Step 300
300
#90CBDE
oklch(80.8% 0.066 219.9)
-
Step 400
400 (this color)
#51BCDA
oklch(74.5% 0.106 219.4)
-
Step 500
500
#0099B8
oklch(63.1% 0.114 219)
-
Step 600
600
#00809B
oklch(55.5% 0.101 219.5)
-
Step 700
700
#006C83
oklch(49.1% 0.089 219.3)
-
Step 800
800
#00586C
oklch(42.6% 0.078 220.2)
-
Step 900
900
#004A5A
oklch(37.8% 0.068 218.5)
-
Step 950
950
#002C37
oklch(27.1% 0.049 219.4)
#51BCDA 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) | #A9B7DC | 0.089 |
| Deuteranopia (no green cones) | #96A9DA | 0.080 |
| Tritanopia (no blue cones) | #00C6C5 | 0.055 |
| Achromatopsia (no color) | #AFAFAF | 0.106 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51BCDA
#51BCDA
oklch(74.5% 0.106 219.4)
- #E69579
#E69579
oklch(74.5% 0.106 39.8)
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 #51BCDA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.041
- Turquoise Blue #06B1C4 ΔE 0.055
- Deep Sky Blue #00BFFF ΔE 0.056
- Bright Sky Blue #02CCFE ΔE 0.058
- Dark Turquoise #00CED1 ΔE 0.060
- Lightblue #7BC8F6 ΔE 0.063
- Medium Turquoise #48D1CC ΔE 0.069
- Light Cornflower Blue #98C1D9 ΔE 0.070
Use #51BCDA 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.