#51B4E8
Closest named color: Deep Sky Blue (#00BFFF). oklch(73.2% 0.119 234.6), rgb(81, 180, 232).
Aa
Black text reads best on this color (9.04:1).
About this color
#51B4E8 is a medium-light, moderately saturated blue. In OKLCH its lightness is 73%, its chroma 0.119 and its hue 235°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.042 away. Black text reads best on it, at 9.04:1.
| Hue family | Blues |
| Lightness | medium-light (73%) |
| Chroma | moderately saturated (0.119) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 9.04:1 |
| White text | 2.32:1 |
Values
| HEX | #51B4E8 |
| RGB | rgb(81, 180, 232) |
| HSL | hsl(201, 77%, 61%) |
| OKLCH | oklch(73.2% 0.119 234.6) |
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 #51B4E8 | 2.32:1 | Fails | Lc -50.4 | Large or bold text, headings |
| Black text on #51B4E8 | 9.04:1 | AAA | Lc 58.5 | Large or bold text, headings |
| #51B4E8 text on white | 2.32:1 | Fails | Lc 45.5 | Large or bold text, headings |
| #51B4E8 text on black | 9.04:1 | AAA | Lc -56.6 | 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
#EFF7FB
oklch(97.1% 0.01 228.9)
-
Step 100
100
#DDEDF6
oklch(93.7% 0.021 232.1)
-
Step 200
200
#C0DEF1
oklch(88.5% 0.041 235.7)
-
Step 300
300
#91C9EA
oklch(80.9% 0.074 234.8)
-
Step 400
400 (this color)
#51B4E8
oklch(73.2% 0.119 234.6)
-
Step 500
500
#0095CE
oklch(63.2% 0.133 234.7)
-
Step 600
600
#007DAD
oklch(55.6% 0.117 234.3)
-
Step 700
700
#006992
oklch(49.1% 0.103 234.3)
-
Step 800
800
#005679
oklch(42.8% 0.09 234.7)
-
Step 900
900
#004765
oklch(37.6% 0.08 234.9)
-
Step 950
950
#002A3E
oklch(26.9% 0.057 235.2)
#51B4E8 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) | #9BB3EA | 0.074 |
| Deuteranopia (no green cones) | #86A3E7 | 0.063 |
| Tritanopia (no blue cones) | #00C2C5 | 0.080 |
| Achromatopsia (no color) | #AAAAAA | 0.119 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51B4E8
#51B4E8
oklch(73.2% 0.119 234.6)
- #E2935C
#E2935C
oklch(73.2% 0.119 54.6)
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 #51B4E8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.042
- Vivid Sky Blue #4CC9F0 ΔE 0.056
- Bright Sky Blue #02CCFE ΔE 0.065
- Turquoise Blue #06B1C4 ΔE 0.065
- Carolina Blue #8AB8FE ΔE 0.066
- Lightblue #7BC8F6 ΔE 0.070
- Greyblue #77A1B5 ΔE 0.080
- Sky #82CAFC ΔE 0.081
Use #51B4E8 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.