#313C77
Closest named color: Twilight Blue (#0A437A). oklch(37.9% 0.101 272.8), rgb(49, 60, 119).
Aa
White text reads best on this color (10.27:1).
About this color
#313C77 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.101 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.037 away. White text reads best on it, at 10.27:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.101) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.04:1 |
| White text | 10.27:1 |
Values
| HEX | #313C77 |
| RGB | rgb(49, 60, 119) |
| HSL | hsl(231, 42%, 33%) |
| OKLCH | oklch(37.9% 0.101 272.8) |
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 #313C77 | 10.27:1 | AAA | Lc -97.7 | Preferred for body text |
| Black text on #313C77 | 2.04:1 | Fails | Lc 10.3 | Not readable |
| #313C77 text on white | 10.27:1 | AAA | Lc 93.7 | Preferred for body text |
| #313C77 text on black | 2.04:1 | Fails | Lc -8.9 | 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
#F3F5FC
oklch(97.1% 0.01 273.4)
-
Step 100
100
#E5E9F9
oklch(93.6% 0.022 274.7)
-
Step 200
200
#CFD8F6
oklch(88.5% 0.042 272.3)
-
Step 300
300
#B0BEF2
oklch(80.9% 0.075 272.9)
-
Step 400
400
#879BEC
oklch(70.7% 0.121 272.4)
-
Step 500
500
#6B80E6
oklch(63.2% 0.154 272.5)
-
Step 600
600
#5567D4
oklch(55.7% 0.167 272.7)
-
Step 700
700
#4555B8
oklch(49.2% 0.156 272.4)
-
Step 800
800
#394695
oklch(42.8% 0.13 272.7)
-
Step 900
900 (this color)
#313C77
oklch(37.9% 0.101 272.8)
-
Step 950
950
#1C2345
oklch(26.9% 0.064 272.7)
#313C77 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) | #204479 | 0.028 |
| Deuteranopia (no green cones) | #163E76 | 0.029 |
| Tritanopia (no blue cones) | #074953 | 0.090 |
| Achromatopsia (no color) | #414141 | 0.101 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #313C77
#313C77
oklch(37.9% 0.101 272.8)
- #504000
#504000
oklch(37.8% 0.077 92.8)
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 #313C77, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.037
- Dark Slate Blue #483D8B ΔE 0.050
- Cobalt #1E488F ΔE 0.050
- Marine Blue #01386A ΔE 0.053
- Light Navy #155084 ΔE 0.060
- Blueberry #464196 ΔE 0.063
- Dark Grey Blue #29465B ΔE 0.064
- Prussian Blue #1D3557 ΔE 0.065
Use #313C77 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.