#37B5EE
Closest named color: Deep Sky Blue (#00BFFF). oklch(73% 0.134 233), rgb(55, 181, 238).
Aa
Black text reads best on this color (9.00:1).
About this color
#37B5EE is a medium-light, moderately saturated blue. In OKLCH its lightness is 73%, its chroma 0.134 and its hue 233°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.032 away. Black text reads best on it, at 9.00:1.
| Hue family | Blues |
| Lightness | medium-light (73%) |
| Chroma | moderately saturated (0.134) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 9.00:1 |
| White text | 2.33:1 |
Values
| HEX | #37B5EE |
| RGB | rgb(55, 181, 238) |
| HSL | hsl(199, 84%, 57%) |
| OKLCH | oklch(73% 0.134 233) |
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 #37B5EE | 2.33:1 | Fails | Lc -50.5 | Large or bold text, headings |
| Black text on #37B5EE | 9.00:1 | AAA | Lc 58.4 | Large or bold text, headings |
| #37B5EE text on white | 2.33:1 | Fails | Lc 45.6 | Large or bold text, headings |
| #37B5EE text on black | 9.00:1 | AAA | Lc -56.5 | 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
#EEF7FC
oklch(97.1% 0.012 231.7)
-
Step 100
100
#DBEDF8
oklch(93.6% 0.024 234.4)
-
Step 200
200
#BCDFF3
oklch(88.5% 0.046 233.1)
-
Step 300
300
#88CAEE
oklch(80.8% 0.084 233.1)
-
Step 400
400 (this color)
#37B5EE
oklch(73% 0.134 233)
-
Step 500
500
#0095CB
oklch(63% 0.131 233.2)
-
Step 600
600
#007DAB
oklch(55.5% 0.115 233.2)
-
Step 700
700
#006991
oklch(49% 0.102 233.6)
-
Step 800
800
#005677
oklch(42.6% 0.088 233.1)
-
Step 900
900
#004864
oklch(37.8% 0.078 232.8)
-
Step 950
950
#002A3D
oklch(26.9% 0.056 233.8)
#37B5EE 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) | #99B3F1 | 0.086 |
| Deuteranopia (no green cones) | #80A2ED | 0.072 |
| Tritanopia (no blue cones) | #00C4C8 | 0.081 |
| Achromatopsia (no color) | #AAAAAA | 0.135 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #37B5EE
#37B5EE
oklch(73% 0.134 233)
- #E98E51
#E98E51
oklch(73% 0.134 52.9)
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 #37B5EE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.032
- Vivid Sky Blue #4CC9F0 ΔE 0.059
- Bright Sky Blue #02CCFE ΔE 0.061
- Turquoise Blue #06B1C4 ΔE 0.066
- Carolina Blue #8AB8FE ΔE 0.075
- Lightblue #7BC8F6 ΔE 0.078
- Chefchaouen Blue #4895EF ΔE 0.087
- Cornflower Blue #6495ED ΔE 0.088
Use #37B5EE 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.