#51BAFF
Closest named color: Deep Sky Blue (#00BFFF). oklch(75.7% 0.138 240.9), rgb(81, 186, 255).
Aa
Black text reads best on this color (9.81:1).
About this color
#51BAFF is a medium-light, moderately saturated blue. In OKLCH its lightness is 76%, its chroma 0.138 and its hue 241°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.028 away. Black text reads best on it, at 9.81:1.
| Hue family | Blues |
| Lightness | medium-light (76%) |
| Chroma | moderately saturated (0.138) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 9.81:1 |
| White text | 2.13:1 |
Values
| HEX | #51BAFF |
| RGB | rgb(81, 186, 255) |
| HSL | hsl(204, 100%, 66%) |
| OKLCH | oklch(75.7% 0.138 240.9) |
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 #51BAFF | 2.13:1 | Fails | Lc -46.3 | Large or bold text, headings |
| Black text on #51BAFF | 9.81:1 | AAA | Lc 62.3 | Content text, not long reading |
| #51BAFF text on white | 2.13:1 | Fails | Lc 41.7 | Non-text elements, placeholder text |
| #51BAFF text on black | 9.81:1 | AAA | Lc -60.6 | 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
#EFF7FD
oklch(97.2% 0.012 239.9)
-
Step 100
100
#DCECF9
oklch(93.5% 0.025 242.3)
-
Step 200
200
#BEDEF6
oklch(88.5% 0.047 240.5)
-
Step 300
300
#8DC8F4
oklch(80.8% 0.087 241.4)
-
Step 400
400 (this color)
#51BAFF
oklch(75.7% 0.138 240.9)
-
Step 500
500
#0092D9
oklch(63.1% 0.147 241)
-
Step 600
600
#007BB7
oklch(55.7% 0.129 240.7)
-
Step 700
700
#00679B
oklch(49.1% 0.115 241)
-
Step 800
800
#005480
oklch(42.6% 0.1 241.3)
-
Step 900
900
#00466B
oklch(37.7% 0.087 240.8)
-
Step 950
950
#002942
oklch(26.9% 0.063 241.6)
#51BAFF 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) | #9ABBFF | 0.070 |
| Deuteranopia (no green cones) | #82AAFE | 0.056 |
| Tritanopia (no blue cones) | #00CBD2 | 0.096 |
| Achromatopsia (no color) | #B1B1B1 | 0.138 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51BAFF
#51BAFF
oklch(75.7% 0.138 240.9)
- #EF9A4A
#EF9A4A
oklch(75.8% 0.139 61.2)
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 #51BAFF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.028
- Carolina Blue #8AB8FE ΔE 0.051
- Vivid Sky Blue #4CC9F0 ΔE 0.052
- Bright Sky Blue #02CCFE ΔE 0.052
- Lightblue #7BC8F6 ΔE 0.059
- Sky #82CAFC ΔE 0.065
- Light Sky Blue #87CEFA ΔE 0.078
- Pastel Blue #A2BFFE ΔE 0.082
Use #51BAFF 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.