#37399E
Closest named color: Sapphire (#2138AB). oklch(40.9% 0.16 275.8), rgb(55, 57, 158).
Aa
White text reads best on this color (9.36:1).
About this color
#37399E is a dark, vivid blue. In OKLCH its lightness is 41%, its chroma 0.160 and its hue 276°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.034 away. White text reads best on it, at 9.36:1.
| Hue family | Blues |
| Lightness | dark (41%) |
| Chroma | vivid (0.160) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.24:1 |
| White text | 9.36:1 |
Values
| HEX | #37399E |
| RGB | rgb(55, 57, 158) |
| HSL | hsl(239, 48%, 42%) |
| OKLCH | oklch(40.9% 0.16 275.8) |
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 #37399E | 9.36:1 | AAA | Lc -95.5 | Preferred for body text |
| Black text on #37399E | 2.24:1 | Fails | Lc 12.8 | Not readable |
| #37399E text on white | 9.36:1 | AAA | Lc 91.1 | Preferred for body text |
| #37399E text on black | 2.24:1 | Fails | Lc -11.2 | Not readable |
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 800.
-
Step 50
50
#F3F5FE
oklch(97.1% 0.012 276.1)
-
Step 100
100
#E4E9FD
oklch(93.6% 0.028 274.7)
-
Step 200
200
#CFD7FC
oklch(88.5% 0.052 275.7)
-
Step 300
300
#B0BCFD
oklch(80.9% 0.093 276)
-
Step 400
400
#8896FC
oklch(70.6% 0.149 276)
-
Step 500
500
#6D78FA
oklch(63.1% 0.191 275.8)
-
Step 600
600
#585DE9
oklch(55.6% 0.207 275.8)
-
Step 700
700
#494BCB
oklch(49.1% 0.193 275.9)
-
Step 800
800 (this color)
#37399E
oklch(40.9% 0.16 275.8)
-
Step 900
900
#323782
oklch(37.8% 0.124 275.8)
-
Step 950
950
#1D214C
oklch(27.1% 0.078 275.8)
#37399E 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) | #004BA1 | 0.055 |
| Deuteranopia (no green cones) | #00429C | 0.046 |
| Tritanopia (no blue cones) | #005366 | 0.133 |
| Achromatopsia (no color) | #464646 | 0.161 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #37399E
#37399E
oklch(40.9% 0.16 275.8)
- #584900
#584900
oklch(40.9% 0.084 95.5)
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 #37399E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.034
- Blueberry #464196 ΔE 0.035
- Dark Slate Blue #483D8B ΔE 0.044
- Cobalt #1E488F ΔE 0.051
- Indigo Blue #3A18B1 ΔE 0.060
- Imperial Purple #480CA8 ΔE 0.069
- Majorelle Blue #3F37C9 ΔE 0.070
- Blue Blue #2242C7 ΔE 0.071
Use #37399E 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.