#304B90
Closest named color: Cobalt (#1E488F). oklch(43% 0.118 265.6), rgb(48, 75, 144).
Aa
White text reads best on this color (8.28:1).
About this color
#304B90 is a dark, moderately saturated blue. In OKLCH its lightness is 43%, its chroma 0.118 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.021 away. White text reads best on it, at 8.28:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.118) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.53:1 |
| White text | 8.28:1 |
Values
| HEX | #304B90 |
| RGB | rgb(48, 75, 144) |
| HSL | hsl(223, 50%, 38%) |
| OKLCH | oklch(43% 0.118 265.6) |
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 #304B90 | 8.28:1 | AAA | Lc -93.0 | Preferred for body text |
| Black text on #304B90 | 2.53:1 | Fails | Lc 15.6 | Dividers and decoration only |
| #304B90 text on white | 8.28:1 | AAA | Lc 88.3 | Fine for body text |
| #304B90 text on black | 2.53:1 | Fails | Lc -13.8 | 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 800.
-
Step 50
50
#F2F5FC
oklch(97% 0.01 267.4)
-
Step 100
100
#E3EAF8
oklch(93.6% 0.02 264.5)
-
Step 200
200
#CDD9F3
oklch(88.4% 0.038 265.8)
-
Step 300
300
#ABC0EE
oklch(80.8% 0.069 265.7)
-
Step 400
400
#7F9FE6
oklch(70.7% 0.111 265.2)
-
Step 500
500
#6085DF
oklch(63.1% 0.142 265.7)
-
Step 600
600
#476DCC
oklch(55.6% 0.153 265.3)
-
Step 700
700
#395AB1
oklch(49% 0.144 265.7)
-
Step 800
800 (this color)
#304B90
oklch(43% 0.118 265.6)
-
Step 900
900
#2A3F72
oklch(37.8% 0.091 265.4)
-
Step 950
950
#192543
oklch(27% 0.058 266.1)
#304B90 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) | #285393 | 0.022 |
| Deuteranopia (no green cones) | #164A8F | 0.024 |
| Tritanopia (no blue cones) | #005B66 | 0.099 |
| Achromatopsia (no color) | #4E4E4E | 0.119 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #304B90
#304B90
oklch(43% 0.118 265.6)
- #654B00
#654B00
oklch(42.9% 0.088 85.7)
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 #304B90, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.021
- Dusk Blue #26538D ΔE 0.025
- Light Navy #155084 ΔE 0.034
- Blueberry #464196 ΔE 0.039
- Dark Slate Blue #483D8B ΔE 0.046
- Deep Sea Blue #015482 ΔE 0.047
- Twilight #4E518B ΔE 0.047
- Light Navy Blue #2E5A88 ΔE 0.048
Use #304B90 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.