#37AFF4
Closest named color: Deep Sky Blue (#00BFFF). oklch(71.9% 0.144 239.2), rgb(55, 175, 244).
Aa
Black text reads best on this color (8.60:1).
About this color
#37AFF4 is a medium-light, vivid blue. In OKLCH its lightness is 72%, its chroma 0.144 and its hue 239°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.042 away. Black text reads best on it, at 8.60:1.
| Hue family | Blues |
| Lightness | medium-light (72%) |
| Chroma | vivid (0.144) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 8.60:1 |
| White text | 2.44:1 |
Values
| HEX | #37AFF4 |
| RGB | rgb(55, 175, 244) |
| HSL | hsl(202, 90%, 59%) |
| OKLCH | oklch(71.9% 0.144 239.2) |
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 #37AFF4 | 2.44:1 | Fails | Lc -52.6 | Large or bold text, headings |
| Black text on #37AFF4 | 8.60:1 | AAA | Lc 56.4 | Large or bold text, headings |
| #37AFF4 text on white | 2.44:1 | Fails | Lc 47.6 | Large or bold text, headings |
| #37AFF4 text on black | 8.60:1 | AAA | Lc -54.4 | 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
#EFF7FD
oklch(97.2% 0.012 239.9)
-
Step 100
100
#DBEDFA
oklch(93.7% 0.026 239.1)
-
Step 200
200
#BCDEF7
oklch(88.4% 0.05 240)
-
Step 300
300
#89C9F5
oklch(80.9% 0.09 239.4)
-
Step 400
400 (this color)
#37AFF4
oklch(71.9% 0.144 239.2)
-
Step 500
500
#0093D6
oklch(63.1% 0.143 239.3)
-
Step 600
600
#007BB4
oklch(55.5% 0.126 239.3)
-
Step 700
700
#006898
oklch(49.2% 0.11 238.7)
-
Step 800
800
#00557E
oklch(42.8% 0.097 239.2)
-
Step 900
900
#00476A
oklch(37.9% 0.085 239)
-
Step 950
950
#002A41
oklch(27.1% 0.061 239)
#37AFF4 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) | #8EAFF7 | 0.076 |
| Deuteranopia (no green cones) | #759EF3 | 0.061 |
| Tritanopia (no blue cones) | #00C0C7 | 0.094 |
| Achromatopsia (no color) | #A6A6A6 | 0.144 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #37AFF4
#37AFF4
oklch(71.9% 0.144 239.2)
- #E58C3A
#E58C3A
oklch(72% 0.143 59.5)
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 #37AFF4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.042
- Chefchaouen Blue #4895EF ΔE 0.069
- Cornflower Blue #6495ED ΔE 0.071
- Bright Sky Blue #02CCFE ΔE 0.077
- Vivid Sky Blue #4CC9F0 ΔE 0.077
- Turquoise Blue #06B1C4 ΔE 0.077
- Carolina Blue #8AB8FE ΔE 0.078
- Dark Sky Blue #448EE4 ΔE 0.088
Use #37AFF4 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.