#303D81
Closest named color: Cobalt (#1E488F). oklch(38.8% 0.115 271.9), rgb(48, 61, 129).
Aa
White text reads best on this color (9.95:1).
About this color
#303D81 is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.115 and its hue 272°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.038 away. White text reads best on it, at 9.95:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.115) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.11:1 |
| White text | 9.95:1 |
Values
| HEX | #303D81 |
| RGB | rgb(48, 61, 129) |
| HSL | hsl(230, 46%, 35%) |
| OKLCH | oklch(38.8% 0.115 271.9) |
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 #303D81 | 9.95:1 | AAA | Lc -97.0 | Preferred for body text |
| Black text on #303D81 | 2.11:1 | Fails | Lc 11.1 | Not readable |
| #303D81 text on white | 9.95:1 | AAA | Lc 92.8 | Preferred for body text |
| #303D81 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
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E4E9FB
oklch(93.6% 0.025 273.5)
-
Step 200
200
#CED8FA
oklch(88.5% 0.048 272.4)
-
Step 300
300
#ADBEF9
oklch(81% 0.086 271.9)
-
Step 400
400
#839AF6
oklch(70.8% 0.137 271.9)
-
Step 500
500
#667DF2
oklch(63% 0.176 272.1)
-
Step 600
600
#4F63E1
oklch(55.6% 0.192 271.8)
-
Step 700
700
#4151C4
oklch(49.1% 0.179 272)
-
Step 800
800
#35439E
oklch(42.6% 0.148 272)
-
Step 900
900 (this color)
#303D81
oklch(38.8% 0.115 271.9)
-
Step 950
950
#1A224A
oklch(26.9% 0.075 272)
#303D81 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) | #174683 | 0.032 |
| Deuteranopia (no green cones) | #033F80 | 0.037 |
| Tritanopia (no blue cones) | #004D59 | 0.099 |
| Achromatopsia (no color) | #434343 | 0.115 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303D81
#303D81
oklch(38.8% 0.115 271.9)
- #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 #303D81, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.038
- Twilight Blue #0A437A ΔE 0.038
- Dark Slate Blue #483D8B ΔE 0.041
- Blueberry #464196 ΔE 0.050
- Light Navy #155084 ΔE 0.055
- Dusk Blue #26538D ΔE 0.062
- Marine Blue #01386A ΔE 0.062
- Deep Sea Blue #015482 ΔE 0.069
Use #303D81 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.