#313B77
Closest named color: Twilight Blue (#0A437A). oklch(37.7% 0.102 273.4), rgb(49, 59, 119).
Aa
White text reads best on this color (10.38:1).
About this color
#313B77 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.102 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.038 away. White text reads best on it, at 10.38:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.102) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.02:1 |
| White text | 10.38:1 |
Values
| HEX | #313B77 |
| RGB | rgb(49, 59, 119) |
| HSL | hsl(231, 42%, 33%) |
| OKLCH | oklch(37.7% 0.102 273.4) |
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 #313B77 | 10.38:1 | AAA | Lc -97.9 | Preferred for body text |
| Black text on #313B77 | 2.02:1 | Fails | Lc 10.0 | Not readable |
| #313B77 text on white | 10.38:1 | AAA | Lc 93.9 | Preferred for body text |
| #313B77 text on black | 2.02:1 | Fails | Lc -8.6 | 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
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E5E9F9
oklch(93.6% 0.022 274.7)
-
Step 200
200
#D0D8F6
oklch(88.6% 0.042 273.7)
-
Step 300
300
#B0BEF3
oklch(80.9% 0.077 273.1)
-
Step 400
400
#889AED
oklch(70.6% 0.123 273.6)
-
Step 500
500
#6C7FE7
oklch(63.1% 0.157 273.3)
-
Step 600
600
#5666D5
oklch(55.7% 0.17 273.4)
-
Step 700
700
#4654B9
oklch(49.1% 0.159 273.2)
-
Step 800
800
#3A4595
oklch(42.7% 0.131 273.6)
-
Step 900
900 (this color)
#313B77
oklch(37.7% 0.102 273.4)
-
Step 950
950
#1D2346
oklch(27.1% 0.065 273.9)
#313B77 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) | #1E4379 | 0.029 |
| Deuteranopia (no green cones) | #143D76 | 0.031 |
| Tritanopia (no blue cones) | #074853 | 0.090 |
| Achromatopsia (no color) | #404040 | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #313B77
#313B77
oklch(37.7% 0.102 273.4)
- #4F4000
#4F4000
oklch(37.6% 0.077 93.9)
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 #313B77, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.038
- Dark Slate Blue #483D8B ΔE 0.050
- Cobalt #1E488F ΔE 0.052
- Marine Blue #01386A ΔE 0.053
- Light Navy #155084 ΔE 0.062
- Blueberry #464196 ΔE 0.063
- Prussian Blue #1D3557 ΔE 0.064
- Dark Grey Blue #29465B ΔE 0.066
Use #313B77 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.