#51AAEF
Closest named color: Cornflower Blue (#6495ED). oklch(71.3% 0.132 244.7), rgb(81, 170, 239).
Aa
Black text reads best on this color (8.34:1).
About this color
#51AAEF is a medium-light, moderately saturated blue. In OKLCH its lightness is 71%, its chroma 0.132 and its hue 245°. Its hue sits on the cool side of the wheel. The nearest named color is Cornflower Blue (#6495ED), ΔE 0.056 away. Black text reads best on it, at 8.34:1.
| Hue family | Blues |
| Lightness | medium-light (71%) |
| Chroma | moderately saturated (0.132) |
| Temperature | cool |
| Nearest name | Cornflower Blue (#6495ED) |
| Black text | 8.34:1 |
| White text | 2.51:1 |
Values
| HEX | #51AAEF |
| RGB | rgb(81, 170, 239) |
| HSL | hsl(206, 83%, 63%) |
| OKLCH | oklch(71.3% 0.132 244.7) |
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 #51AAEF | 2.51:1 | Fails | Lc -54.2 | Large or bold text, headings |
| Black text on #51AAEF | 8.34:1 | AAA | Lc 54.9 | Large or bold text, headings |
| #51AAEF text on white | 2.51:1 | Fails | Lc 49.1 | Large or bold text, headings |
| #51AAEF text on black | 8.34:1 | AAA | Lc -52.9 | 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
#F0F6FD
oklch(97.1% 0.011 252.1)
-
Step 100
100
#DDECF9
oklch(93.6% 0.024 244.1)
-
Step 200
200
#C1DDF6
oklch(88.5% 0.046 245.3)
-
Step 300
300
#93C7F3
oklch(80.9% 0.083 244.6)
-
Step 400
400 (this color)
#51AAEF
oklch(71.3% 0.132 244.7)
-
Step 500
500
#0090E1
oklch(63.1% 0.158 244.7)
-
Step 600
600
#0079BE
oklch(55.6% 0.139 244.6)
-
Step 700
700
#0066A1
oklch(49.2% 0.123 244.5)
-
Step 800
800
#005385
oklch(42.7% 0.107 244.8)
-
Step 900
900
#004570
oklch(37.7% 0.095 244.9)
-
Step 950
950
#002945
oklch(27.1% 0.068 244.5)
#51AAEF 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) | #8BACF2 | 0.059 |
| Deuteranopia (no green cones) | #759CEE | 0.046 |
| Tritanopia (no blue cones) | #00BBC2 | 0.098 |
| Achromatopsia (no color) | #A3A3A3 | 0.132 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51AAEF
#51AAEF
oklch(71.3% 0.132 244.7)
- #DB8F3D
#DB8F3D
oklch(71.3% 0.133 64.5)
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 #51AAEF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cornflower Blue #6495ED ΔE 0.056
- Deep Sky Blue #00BFFF ΔE 0.057
- Chefchaouen Blue #4895EF ΔE 0.059
- Carolina Blue #8AB8FE ΔE 0.073
- Dark Sky Blue #448EE4 ΔE 0.078
- Periwinkle Blue #8F99FB ΔE 0.079
- Turquoise Blue #06B1C4 ΔE 0.081
- Vivid Sky Blue #4CC9F0 ΔE 0.085
Use #51AAEF 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.