#31B9FA
Closest named color: Deep Sky Blue (#00BFFF). oklch(74.4% 0.145 235.2), rgb(49, 185, 250).
Aa
Black text reads best on this color (9.45:1).
About this color
#31B9FA is a medium-light, vivid blue. In OKLCH its lightness is 74%, its chroma 0.145 and its hue 235°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.017 away. Black text reads best on it, at 9.45:1.
| Hue family | Blues |
| Lightness | medium-light (74%) |
| Chroma | vivid (0.145) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 9.45:1 |
| White text | 2.22:1 |
Values
| HEX | #31B9FA |
| RGB | rgb(49, 185, 250) |
| HSL | hsl(199, 95%, 59%) |
| OKLCH | oklch(74.4% 0.145 235.2) |
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 #31B9FA | 2.22:1 | Fails | Lc -48.1 | Large or bold text, headings |
| Black text on #31B9FA | 9.45:1 | AAA | Lc 60.7 | Content text, not long reading |
| #31B9FA text on white | 2.22:1 | Fails | Lc 43.3 | Non-text elements, placeholder text |
| #31B9FA text on black | 9.45:1 | AAA | Lc -58.9 | 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
#EEF7FD
oklch(97.1% 0.013 236.6)
-
Step 100
100
#DAEDF9
oklch(93.6% 0.026 235.4)
-
Step 200
200
#BADFF6
oklch(88.4% 0.05 235.4)
-
Step 300
300
#85CAF3
oklch(80.8% 0.091 235.6)
-
Step 400
400 (this color)
#31B9FA
oklch(74.4% 0.145 235.2)
-
Step 500
500
#0094CF
oklch(63% 0.135 235.8)
-
Step 600
600
#007DAE
oklch(55.7% 0.118 234.9)
-
Step 700
700
#006993
oklch(49.2% 0.104 234.9)
-
Step 800
800
#005679
oklch(42.8% 0.09 234.7)
-
Step 900
900
#004766
oklch(37.6% 0.081 235.8)
-
Step 950
950
#002A3E
oklch(26.9% 0.057 235.2)
#31B9FA 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) | #99B8FD | 0.087 |
| Deuteranopia (no green cones) | #7FA6F9 | 0.072 |
| Tritanopia (no blue cones) | #00CACF | 0.091 |
| Achromatopsia (no color) | #AEAEAE | 0.145 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #31B9FA
#31B9FA
oklch(74.4% 0.145 235.2)
- #F19148
#F19148
oklch(74.5% 0.145 55.3)
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 #31B9FA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.017
- Bright Sky Blue #02CCFE ΔE 0.051
- Vivid Sky Blue #4CC9F0 ΔE 0.054
- Carolina Blue #8AB8FE ΔE 0.070
- Lightblue #7BC8F6 ΔE 0.072
- Sky #82CAFC ΔE 0.080
- Turquoise Blue #06B1C4 ΔE 0.082
- Light Sky Blue #87CEFA ΔE 0.092
Use #31B9FA 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.