#51ADD9
Closest named color: Turquoise Blue (#06B1C4). oklch(71% 0.108 231.8), rgb(81, 173, 217).
Aa
Black text reads best on this color (8.32:1).
About this color
#51ADD9 is a medium-light, moderately saturated blue. In OKLCH its lightness is 71%, its chroma 0.108 and its hue 232°. Its hue sits on the cool side of the wheel. The nearest named color is Turquoise Blue (#06B1C4), ΔE 0.049 away. Black text reads best on it, at 8.32:1.
| Hue family | Blues |
| Lightness | medium-light (71%) |
| Chroma | moderately saturated (0.108) |
| Temperature | cool |
| Nearest name | Turquoise Blue (#06B1C4) |
| Black text | 8.32:1 |
| White text | 2.52:1 |
Values
| HEX | #51ADD9 |
| RGB | rgb(81, 173, 217) |
| HSL | hsl(199, 64%, 58%) |
| OKLCH | oklch(71% 0.108 231.8) |
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 #51ADD9 | 2.52:1 | Fails | Lc -54.3 | Large or bold text, headings |
| Black text on #51ADD9 | 8.32:1 | AAA | Lc 54.8 | Large or bold text, headings |
| #51ADD9 text on white | 2.52:1 | Fails | Lc 49.2 | Large or bold text, headings |
| #51ADD9 text on black | 8.32:1 | AAA | Lc -52.8 | 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
#F0F7FB
oklch(97.2% 0.009 232.4)
-
Step 100
100
#DEEDF5
oklch(93.7% 0.019 230.7)
-
Step 200
200
#C1DEEE
oklch(88.4% 0.038 232)
-
Step 300
300
#94C9E5
oklch(80.9% 0.068 231.7)
-
Step 400
400 (this color)
#51ADD9
oklch(71% 0.108 231.8)
-
Step 500
500
#0096C9
oklch(63.2% 0.128 231.5)
-
Step 600
600
#007EAA
oklch(55.7% 0.113 231.8)
-
Step 700
700
#006A8F
oklch(49.2% 0.1 231.3)
-
Step 800
800
#005676
oklch(42.6% 0.087 232.3)
-
Step 900
900
#004863
oklch(37.7% 0.077 231.8)
-
Step 950
950
#002B3C
oklch(27.1% 0.054 230.4)
#51ADD9 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) | #97ABDB | 0.072 |
| Deuteranopia (no green cones) | #849DD8 | 0.062 |
| Tritanopia (no blue cones) | #00B9BC | 0.070 |
| Achromatopsia (no color) | #A3A3A3 | 0.108 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51ADD9
#51ADD9
oklch(71% 0.108 231.8)
- #D78D60
#D78D60
oklch(70.9% 0.109 51.5)
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 #51ADD9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Turquoise Blue #06B1C4 ΔE 0.049
- Greyblue #77A1B5 ΔE 0.059
- Deep Sky Blue #00BFFF ΔE 0.064
- Bluegrey #85A3B2 ΔE 0.069
- Bluey Grey #89A0B0 ΔE 0.075
- Vivid Sky Blue #4CC9F0 ΔE 0.076
- Cornflower Blue #6495ED ΔE 0.079
- Chefchaouen Blue #4895EF ΔE 0.082
Use #51ADD9 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.