#31388C
Closest named color: Dark Slate Blue (#483D8B). oklch(38.7% 0.138 274.4), rgb(49, 56, 140).
Aa
White text reads best on this color (10.12:1).
About this color
#31388C is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.138 and its hue 274°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.040 away. White text reads best on it, at 10.12:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.138) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.07:1 |
| White text | 10.12:1 |
Values
| HEX | #31388C |
| RGB | rgb(49, 56, 140) |
| HSL | hsl(235, 48%, 37%) |
| OKLCH | oklch(38.7% 0.138 274.4) |
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 #31388C | 10.12:1 | AAA | Lc -97.2 | Preferred for body text |
| Black text on #31388C | 2.07:1 | Fails | Lc 10.8 | Not readable |
| #31388C text on white | 10.12:1 | AAA | Lc 93.1 | Preferred for body text |
| #31388C text on black | 2.07:1 | Fails | Lc -9.4 | 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
#E3E9FF
oklch(93.6% 0.03 273.6)
-
Step 200
200
#CDD7FF
oklch(88.4% 0.056 274.2)
-
Step 300
300
#ADBCFF
oklch(80.8% 0.096 274.3)
-
Step 400
400
#8597FF
oklch(70.8% 0.153 274.4)
-
Step 500
500
#6978FF
oklch(63.1% 0.199 274.4)
-
Step 600
600
#5359F6
oklch(55.7% 0.229 274.4)
-
Step 700
700
#4447D6
oklch(49.1% 0.213 274.3)
-
Step 800
800
#373CAD
oklch(42.8% 0.176 274.1)
-
Step 900
900 (this color)
#31388C
oklch(38.7% 0.138 274.4)
-
Step 950
950
#1B2050
oklch(27% 0.087 274.5)
#31388C 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) | #00468F | 0.047 |
| Deuteranopia (no green cones) | #003E8A | 0.041 |
| Tritanopia (no blue cones) | #004C5C | 0.115 |
| Achromatopsia (no color) | #424242 | 0.138 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #31388C
#31388C
oklch(38.7% 0.138 274.4)
- #524300
#524300
oklch(38.7% 0.079 94.4)
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 #31388C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.040
- Cobalt #1E488F ΔE 0.043
- Blueberry #464196 ΔE 0.045
- Sapphire #2138AB ΔE 0.054
- Twilight Blue #0A437A ΔE 0.055
- Light Navy #155084 ΔE 0.070
- Dusk Blue #26538D ΔE 0.073
- Marine Blue #01386A ΔE 0.075
Use #31388C 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.