#313B78
Closest named color: Twilight Blue (#0A437A). oklch(37.8% 0.104 273.4), rgb(49, 59, 120).
Aa
White text reads best on this color (10.35:1).
About this color
#313B78 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.104 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 10.35:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.104) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.02:1 |
| White text | 10.35:1 |
Values
| HEX | #313B78 |
| RGB | rgb(49, 59, 120) |
| HSL | hsl(232, 42%, 33%) |
| OKLCH | oklch(37.8% 0.104 273.4) |
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 #313B78 | 10.35:1 | AAA | Lc -97.9 | Preferred for body text |
| Black text on #313B78 | 2.02:1 | Fails | Lc 10.1 | Not readable |
| #313B78 text on white | 10.35:1 | AAA | Lc 93.8 | Preferred for body text |
| #313B78 text on black | 2.02:1 | Fails | Lc -8.7 | 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
#CFD8F7
oklch(88.5% 0.044 272.7)
-
Step 300
300
#B0BEF4
oklch(81% 0.078 273.3)
-
Step 400
400
#889AEE
oklch(70.7% 0.125 273.6)
-
Step 500
500
#6C7FE8
oklch(63.2% 0.158 273.3)
-
Step 600
600
#5565D7
oklch(55.5% 0.174 273.3)
-
Step 700
700
#4653BA
oklch(49% 0.161 273.5)
-
Step 800
800
#394596
oklch(42.7% 0.132 273.1)
-
Step 900
900 (this color)
#313B78
oklch(37.8% 0.104 273.4)
-
Step 950
950
#1C2346
oklch(27% 0.065 272.8)
#313B78 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) | #1D437A | 0.029 |
| Deuteranopia (no green cones) | #123D77 | 0.033 |
| Tritanopia (no blue cones) | #054953 | 0.093 |
| Achromatopsia (no color) | #404040 | 0.104 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #313B78
#313B78
oklch(37.8% 0.104 273.4)
- #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 #313B78, 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 0.049
- Cobalt #1E488F ΔE 0.050
- Marine Blue #01386A ΔE 0.054
- Light Navy #155084 ΔE 0.062
- Blueberry #464196 ΔE 0.062
- Prussian Blue #1D3557 ΔE 0.066
- Dark Grey Blue #29465B ΔE 0.067
Use #313B78 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.