#31378B
Closest named color: Dark Slate Blue (#483D8B). oklch(38.4% 0.138 274.8), rgb(49, 55, 139).
Aa
White text reads best on this color (10.24:1).
About this color
#31378B is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.138 and its hue 275°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.041 away. White text reads best on it, at 10.24:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.138) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.04:1 |
| White text | 10.24:1 |
Values
| HEX | #31378B |
| RGB | rgb(49, 55, 139) |
| HSL | hsl(236, 48%, 37%) |
| OKLCH | oklch(38.4% 0.138 274.8) |
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 #31378B | 10.24:1 | AAA | Lc -97.5 | Preferred for body text |
| Black text on #31378B | 2.04:1 | Fails | Lc 10.5 | Not readable |
| #31378B text on white | 10.24:1 | AAA | Lc 93.4 | Preferred for body text |
| #31378B text on black | 2.04:1 | Fails | Lc -9.1 | 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
#F2F5FF
oklch(97.1% 0.014 272.7)
-
Step 100
100
#E4E9FE
oklch(93.7% 0.029 275.2)
-
Step 200
200
#CED7FF
oklch(88.5% 0.056 275.2)
-
Step 300
300
#AEBCFF
oklch(80.9% 0.096 274.9)
-
Step 400
400
#8596FF
oklch(70.6% 0.154 274.8)
-
Step 500
500
#6A78FF
oklch(63.2% 0.198 274.8)
-
Step 600
600
#5458F5
oklch(55.6% 0.229 274.9)
-
Step 700
700
#4546D6
oklch(49% 0.214 274.8)
-
Step 800
800
#383BAD
oklch(42.7% 0.177 274.8)
-
Step 900
900 (this color)
#31378B
oklch(38.4% 0.138 274.8)
-
Step 950
950
#1B2050
oklch(27% 0.087 274.5)
#31378B 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) | #00458E | 0.047 |
| Deuteranopia (no green cones) | #003D89 | 0.041 |
| Tritanopia (no blue cones) | #004B5B | 0.115 |
| Achromatopsia (no color) | #414141 | 0.138 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #31378B
#31378B
oklch(38.4% 0.138 274.8)
- #514200
#514200
oklch(38.4% 0.079 94.3)
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 #31378B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.041
- Cobalt #1E488F ΔE 0.046
- Blueberry #464196 ΔE 0.047
- Twilight Blue #0A437A ΔE 0.055
- Sapphire #2138AB ΔE 0.055
- Light Navy #155084 ΔE 0.072
- Marine Blue #01386A ΔE 0.074
- Dusk Blue #26538D ΔE 0.076
Use #31378B 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.