#313A78
Closest named color: Twilight Blue (#0A437A). oklch(37.5% 0.105 274), rgb(49, 58, 120).
Aa
White text reads best on this color (10.46:1).
About this color
#313A78 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.105 and its hue 274°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.040 away. White text reads best on it, at 10.46:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.105) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.00:1 |
| White text | 10.46:1 |
Values
| HEX | #313A78 |
| RGB | rgb(49, 58, 120) |
| HSL | hsl(232, 42%, 33%) |
| OKLCH | oklch(37.5% 0.105 274) |
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 #313A78 | 10.46:1 | AAA | Lc -98.1 | Preferred for body text |
| Black text on #313A78 | 2.00:1 | Fails | Lc 9.9 | Not readable |
| #313A78 text on white | 10.46:1 | AAA | Lc 94.1 | Preferred for body text |
| #313A78 text on black | 2.00:1 | Fails | Lc -8.5 | 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
#E5E9FA
oklch(93.6% 0.023 275.4)
-
Step 200
200
#D0D8F7
oklch(88.6% 0.044 274)
-
Step 300
300
#B0BEF4
oklch(81% 0.078 273.3)
-
Step 400
400
#889AEF
oklch(70.7% 0.126 273.7)
-
Step 500
500
#6D7EEA
oklch(63.1% 0.162 274.1)
-
Step 600
600
#5665D8
oklch(55.7% 0.175 273.7)
-
Step 700
700
#4753BB
oklch(49.2% 0.162 273.8)
-
Step 800
800
#3A4497
oklch(42.6% 0.135 274)
-
Step 900
900 (this color)
#313A78
oklch(37.5% 0.105 274)
-
Step 950
950
#1D2347
oklch(27.1% 0.067 274)
#313A78 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) | #1B437A | 0.032 |
| Deuteranopia (no green cones) | #0F3D77 | 0.035 |
| Tritanopia (no blue cones) | #064853 | 0.093 |
| Achromatopsia (no color) | #3F3F3F | 0.106 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #313A78
#313A78
oklch(37.5% 0.105 274)
- #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 #313A78, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.040
- Dark Slate Blue #483D8B ΔE 0.050
- Cobalt #1E488F ΔE 0.052
- Marine Blue #01386A ΔE 0.053
- Blueberry #464196 ΔE 0.063
- Light Navy #155084 ΔE 0.064
- Prussian Blue #1D3557 ΔE 0.066
- Dark Grey Blue #29465B ΔE 0.069
Use #313A78 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.