#313F78
Closest named color: Twilight Blue (#0A437A). oklch(38.6% 0.098 270.8), rgb(49, 63, 120).
Aa
White text reads best on this color (9.93:1).
About this color
#313F78 is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.098 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.034 away. White text reads best on it, at 9.93:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.098) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.11:1 |
| White text | 9.93:1 |
Values
| HEX | #313F78 |
| RGB | rgb(49, 63, 120) |
| HSL | hsl(228, 42%, 33%) |
| OKLCH | oklch(38.6% 0.098 270.8) |
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 #313F78 | 9.93:1 | AAA | Lc -97.0 | Preferred for body text |
| Black text on #313F78 | 2.11:1 | Fails | Lc 11.1 | Not readable |
| #313F78 text on white | 9.93:1 | AAA | Lc 92.9 | Preferred for body text |
| #313F78 text on black | 2.11:1 | Fails | Lc -9.6 | 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
#F3F5FC
oklch(97.1% 0.01 273.4)
-
Step 100
100
#E4E9F9
oklch(93.5% 0.022 272.1)
-
Step 200
200
#CFD8F5
oklch(88.4% 0.041 271.9)
-
Step 300
300
#AFBFF1
oklch(81% 0.073 270.9)
-
Step 400
400
#859CEA
oklch(70.7% 0.117 270.7)
-
Step 500
500
#6881E4
oklch(63.1% 0.151 270.9)
-
Step 600
600
#5168D2
oklch(55.5% 0.165 270.9)
-
Step 700
700
#4256B6
oklch(49.1% 0.153 270.9)
-
Step 800
800
#364793
oklch(42.7% 0.126 270.7)
-
Step 900
900 (this color)
#313F78
oklch(38.6% 0.098 270.8)
-
Step 950
950
#1B2445
oklch(27.1% 0.063 270.3)
#313F78 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) | #25467A | 0.023 |
| Deuteranopia (no green cones) | #1B4077 | 0.025 |
| Tritanopia (no blue cones) | #044C55 | 0.089 |
| Achromatopsia (no color) | #434343 | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #313F78
#313F78
oklch(38.6% 0.098 270.8)
- #544200
#544200
oklch(38.7% 0.079 91.1)
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 #313F78, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.034
- Cobalt #1E488F ΔE 0.045
- Dark Slate Blue #483D8B ΔE 0.048
- Light Navy #155084 ΔE 0.052
- Marine Blue #01386A ΔE 0.057
- Blueberry #464196 ΔE 0.060
- Dark Grey Blue #29465B ΔE 0.060
- Dusk Blue #26538D ΔE 0.062
Use #313F78 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.