#303C78
Closest named color: Twilight Blue (#0A437A). oklch(37.9% 0.103 272.1), rgb(48, 60, 120).
Aa
White text reads best on this color (10.27:1).
About this color
#303C78 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.103 and its hue 272°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.036 away. White text reads best on it, at 10.27:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.103) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.04:1 |
| White text | 10.27:1 |
Values
| HEX | #303C78 |
| RGB | rgb(48, 60, 120) |
| HSL | hsl(230, 43%, 33%) |
| OKLCH | oklch(37.9% 0.103 272.1) |
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 #303C78 | 10.27:1 | AAA | Lc -97.7 | Preferred for body text |
| Black text on #303C78 | 2.04:1 | Fails | Lc 10.3 | Not readable |
| #303C78 text on white | 10.27:1 | AAA | Lc 93.7 | Preferred for body text |
| #303C78 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
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E4E9F9
oklch(93.5% 0.022 272.1)
-
Step 200
200
#CFD8F6
oklch(88.5% 0.042 272.3)
-
Step 300
300
#AFBEF3
oklch(80.9% 0.077 272.3)
-
Step 400
400
#869BED
oklch(70.7% 0.123 272)
-
Step 500
500
#6A80E8
oklch(63.2% 0.157 272.2)
-
Step 600
600
#5366D6
oklch(55.5% 0.172 272.3)
-
Step 700
700
#4454B9
oklch(49% 0.159 272.4)
-
Step 800
800
#384696
oklch(42.8% 0.131 272.2)
-
Step 900
900 (this color)
#303C78
oklch(37.9% 0.103 272.1)
-
Step 950
950
#1C2346
oklch(27% 0.065 272.8)
#303C78 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) | #1F447A | 0.027 |
| Deuteranopia (no green cones) | #143E77 | 0.029 |
| Tritanopia (no blue cones) | #004954 | 0.091 |
| Achromatopsia (no color) | #414141 | 0.103 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303C78
#303C78
oklch(37.9% 0.103 272.1)
- #514000
#514000
oklch(37.9% 0.077 91.7)
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 #303C78, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.036
- Cobalt #1E488F ΔE 0.049
- Dark Slate Blue #483D8B ΔE 0.050
- Marine Blue #01386A ΔE 0.053
- Light Navy #155084 ΔE 0.059
- Blueberry #464196 ΔE 0.062
- Dark Grey Blue #29465B ΔE 0.065
- Prussian Blue #1D3557 ΔE 0.066
Use #303C78 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.