#51BDED
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(75.5% 0.12 230.5), rgb(81, 189, 237).
Aa
Black text reads best on this color (9.85:1).
About this color
#51BDED is a medium-light, moderately saturated blue. In OKLCH its lightness is 76%, its chroma 0.120 and its hue 231°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.032 away. Black text reads best on it, at 9.85:1.
| Hue family | Blues |
| Lightness | medium-light (76%) |
| Chroma | moderately saturated (0.120) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 9.85:1 |
| White text | 2.13:1 |
Values
| HEX | #51BDED |
| RGB | rgb(81, 189, 237) |
| HSL | hsl(198, 81%, 62%) |
| OKLCH | oklch(75.5% 0.12 230.5) |
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 #51BDED | 2.13:1 | Fails | Lc -46.2 | Large or bold text, headings |
| Black text on #51BDED | 9.85:1 | AAA | Lc 62.4 | Content text, not long reading |
| #51BDED text on white | 2.13:1 | Fails | Lc 41.5 | Non-text elements, placeholder text |
| #51BDED text on black | 9.85:1 | AAA | Lc -60.7 | 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 400.
-
Step 50
50
#EFF7FB
oklch(97.1% 0.01 228.9)
-
Step 100
100
#DCEDF6
oklch(93.6% 0.022 230.5)
-
Step 200
200
#BEDFF0
oklch(88.5% 0.042 230.2)
-
Step 300
300
#8ECAE8
oklch(80.9% 0.075 230.5)
-
Step 400
400 (this color)
#51BDED
oklch(75.5% 0.12 230.5)
-
Step 500
500
#0096C7
oklch(63.1% 0.126 230.5)
-
Step 600
600
#007EA8
oklch(55.6% 0.112 230.6)
-
Step 700
700
#006A8E
oklch(49.1% 0.099 230.6)
-
Step 800
800
#005775
oklch(42.8% 0.086 230.3)
-
Step 900
900
#004862
oklch(37.7% 0.076 230.8)
-
Step 950
950
#002B3C
oklch(27.1% 0.054 230.4)
#51BDED 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) | #A5BAEF | 0.083 |
| Deuteranopia (no green cones) | #8FABEC | 0.070 |
| Tritanopia (no blue cones) | #00CACD | 0.073 |
| Achromatopsia (no color) | #B2B2B2 | 0.120 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51BDED
#51BDED
oklch(75.5% 0.12 230.5)
- #EC9867
#EC9867
oklch(75.4% 0.12 50.4)
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 #51BDED, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.032
- Deep Sky Blue #00BFFF ΔE 0.034
- Bright Sky Blue #02CCFE ΔE 0.044
- Lightblue #7BC8F6 ΔE 0.050
- Carolina Blue #8AB8FE ΔE 0.061
- Sky #82CAFC ΔE 0.061
- Sky Blue #87CEEB ΔE 0.071
- Light Sky Blue #87CEFA ΔE 0.071
Use #51BDED 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.