#31C5E9
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(76.4% 0.128 218.9), rgb(49, 197, 233).
Aa
Black text reads best on this color (10.29:1).
About this color
#31C5E9 is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 76%, its chroma 0.128 and its hue 219°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.021 away. Black text reads best on it, at 10.29:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (76%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 10.29:1 |
| White text | 2.04:1 |
Values
| HEX | #31C5E9 |
| RGB | rgb(49, 197, 233) |
| HSL | hsl(192, 81%, 55%) |
| OKLCH | oklch(76.4% 0.128 218.9) |
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 #31C5E9 | 2.04:1 | Fails | Lc -43.7 | Non-text elements, placeholder text |
| Black text on #31C5E9 | 10.29:1 | AAA | Lc 64.7 | Content text, not long reading |
| #31C5E9 text on white | 2.04:1 | Fails | Lc 39.2 | Non-text elements, placeholder text |
| #31C5E9 text on black | 10.29:1 | AAA | Lc -63.1 | 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 300.
-
Step 50
50
#EAF9FD
oklch(97.2% 0.017 215.5)
-
Step 100
100
#D0F0FB
oklch(93.5% 0.037 220.5)
-
Step 200
200
#A4E5F9
oklch(88.5% 0.071 218.9)
-
Step 300
300 (this color)
#31C5E9
oklch(76.4% 0.128 218.9)
-
Step 400
400
#00B3D6
oklch(70.8% 0.128 218.5)
-
Step 500
500
#0099B8
oklch(63.1% 0.114 219)
-
Step 600
600
#00819B
oklch(55.7% 0.1 218.5)
-
Step 700
700
#006C83
oklch(49.1% 0.089 219.3)
-
Step 800
800
#00586B
oklch(42.5% 0.077 219.1)
-
Step 900
900
#004A5A
oklch(37.8% 0.068 218.5)
-
Step 950
950
#002C36
oklch(27% 0.048 217.4)
#31C5E9 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) | #AEBFEB | 0.108 |
| Deuteranopia (no green cones) | #96AEE9 | 0.096 |
| Tritanopia (no blue cones) | #00D1D0 | 0.058 |
| Achromatopsia (no color) | #B5B5B5 | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #31C5E9
#31C5E9
oklch(76.4% 0.128 218.9)
- #F79574
#F79574
oklch(76.5% 0.127 39.3)
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 #31C5E9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.021
- Bright Sky Blue #02CCFE ΔE 0.031
- Deep Sky Blue #00BFFF ΔE 0.041
- Dark Turquoise #00CED1 ΔE 0.051
- Aqua Blue #02D8E9 ΔE 0.053
- Lightblue #7BC8F6 ΔE 0.057
- Medium Turquoise #48D1CC ΔE 0.063
- Sky #82CAFC ΔE 0.068
Use #31C5E9 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.