#37398B
Closest named color: Dark Slate Blue (#483D8B). oklch(39.3% 0.133 277.3), rgb(55, 57, 139).
Aa
White text reads best on this color (9.90:1).
About this color
#37398B is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.133 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.031 away. White text reads best on it, at 9.90:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.133) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.12:1 |
| White text | 9.90:1 |
Values
| HEX | #37398B |
| RGB | rgb(55, 57, 139) |
| HSL | hsl(239, 43%, 38%) |
| OKLCH | oklch(39.3% 0.133 277.3) |
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 #37398B | 9.90:1 | AAA | Lc -96.8 | Preferred for body text |
| Black text on #37398B | 2.12:1 | Fails | Lc 11.3 | Not readable |
| #37398B text on white | 9.90:1 | AAA | Lc 92.6 | Preferred for body text |
| #37398B text on black | 2.12:1 | Fails | Lc -9.8 | 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 900.
-
Step 50
50
#F3F5FF
oklch(97.2% 0.013 277.1)
-
Step 100
100
#E5E9FE
oklch(93.7% 0.029 277.2)
-
Step 200
200
#CFD6FE
oklch(88.4% 0.056 277.4)
-
Step 300
300
#B1BBFF
oklch(80.9% 0.097 277.5)
-
Step 400
400
#8A95FF
oklch(70.7% 0.154 277.2)
-
Step 500
500
#7075FF
oklch(63.1% 0.201 277.4)
-
Step 600
600
#5B58F1
oklch(55.7% 0.222 277.2)
-
Step 700
700
#4C46D2
oklch(49.1% 0.207 277.4)
-
Step 800
800
#3D3BA9
oklch(42.6% 0.171 277.1)
-
Step 900
900 (this color)
#37398B
oklch(39.3% 0.133 277.3)
-
Step 950
950
#1E204E
oklch(27.1% 0.083 277.4)
#37398B 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) | #00478E | 0.053 |
| Deuteranopia (no green cones) | #003F89 | 0.048 |
| Tritanopia (no blue cones) | #004C5C | 0.115 |
| Achromatopsia (no color) | #434343 | 0.134 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #37398B
#37398B
oklch(39.3% 0.133 277.3)
- #524500
#524500
oklch(39.2% 0.081 96.9)
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 #37398B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.031
- Blueberry #464196 ΔE 0.037
- Cobalt #1E488F ΔE 0.044
- Twilight Blue #0A437A ΔE 0.058
- Sapphire #2138AB ΔE 0.059
- Light Navy #155084 ΔE 0.070
- Dusk Blue #26538D ΔE 0.071
- Twilight #4E518B ΔE 0.078
Use #37398B 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.