#51AEEF
Closest named color: Deep Sky Blue (#00BFFF). oklch(72.2% 0.129 242.1), rgb(81, 174, 239).
Aa
Black text reads best on this color (8.65:1).
About this color
#51AEEF is a medium-light, moderately saturated blue. In OKLCH its lightness is 72%, its chroma 0.129 and its hue 242°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.048 away. Black text reads best on it, at 8.65:1.
| Hue family | Blues |
| Lightness | medium-light (72%) |
| Chroma | moderately saturated (0.129) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 8.65:1 |
| White text | 2.42:1 |
Values
| HEX | #51AEEF |
| RGB | rgb(81, 174, 239) |
| HSL | hsl(205, 83%, 63%) |
| OKLCH | oklch(72.2% 0.129 242.1) |
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 #51AEEF | 2.42:1 | Fails | Lc -52.5 | Large or bold text, headings |
| Black text on #51AEEF | 8.65:1 | AAA | Lc 56.5 | Large or bold text, headings |
| #51AEEF text on white | 2.42:1 | Fails | Lc 47.5 | Large or bold text, headings |
| #51AEEF text on black | 8.65:1 | AAA | Lc -54.5 | 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
#EFF7FC
oklch(97.2% 0.011 234.8)
-
Step 100
100
#DDECF9
oklch(93.6% 0.024 244.1)
-
Step 200
200
#C0DDF5
oklch(88.4% 0.045 243.2)
-
Step 300
300
#92C8F1
oklch(81% 0.081 241.7)
-
Step 400
400 (this color)
#51AEEF
oklch(72.2% 0.129 242.1)
-
Step 500
500
#0092DB
oklch(63.2% 0.149 241.7)
-
Step 600
600
#007AB9
oklch(55.5% 0.132 242.1)
-
Step 700
700
#00679D
oklch(49.2% 0.117 242)
-
Step 800
800
#005481
oklch(42.7% 0.101 241.9)
-
Step 900
900
#00466D
oklch(37.8% 0.09 242.2)
-
Step 950
950
#002943
oklch(27% 0.065 242.6)
#51AEEF 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) | #91AFF2 | 0.064 |
| Deuteranopia (no green cones) | #7B9FEE | 0.052 |
| Tritanopia (no blue cones) | #00BEC5 | 0.092 |
| Achromatopsia (no color) | #A6A6A6 | 0.129 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51AEEF
#51AEEF
oklch(72.2% 0.129 242.1)
- #DE9147
#DE9147
oklch(72.1% 0.129 62)
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 #51AEEF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.048
- Cornflower Blue #6495ED ΔE 0.067
- Carolina Blue #8AB8FE ΔE 0.067
- Chefchaouen Blue #4895EF ΔE 0.070
- Vivid Sky Blue #4CC9F0 ΔE 0.074
- Turquoise Blue #06B1C4 ΔE 0.077
- Bright Sky Blue #02CCFE ΔE 0.079
- Lightblue #7BC8F6 ΔE 0.084
Use #51AEEF 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.