#304B8D
Closest named color: Cobalt (#1E488F). oklch(42.8% 0.114 265.2), rgb(48, 75, 141).
Aa
White text reads best on this color (8.34:1).
About this color
#304B8D is a dark, moderately saturated blue. In OKLCH its lightness is 43%, its chroma 0.114 and its hue 265°. 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 8.34:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.114) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.51:1 |
| White text | 8.34:1 |
Values
| HEX | #304B8D |
| RGB | rgb(48, 75, 141) |
| HSL | hsl(223, 49%, 37%) |
| OKLCH | oklch(42.8% 0.114 265.2) |
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 #304B8D | 8.34:1 | AAA | Lc -93.1 | Preferred for body text |
| Black text on #304B8D | 2.51:1 | Fails | Lc 15.4 | Dividers and decoration only |
| #304B8D text on white | 8.34:1 | AAA | Lc 88.5 | Fine for body text |
| #304B8D text on black | 2.51:1 | Fails | Lc -13.6 | 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 800.
-
Step 50
50
#F2F5FC
oklch(97% 0.01 267.4)
-
Step 100
100
#E4EAF7
oklch(93.6% 0.019 266)
-
Step 200
200
#CDD9F2
oklch(88.4% 0.037 265.1)
-
Step 300
300
#ACC1ED
oklch(81% 0.067 264.9)
-
Step 400
400
#809FE4
oklch(70.7% 0.107 265.3)
-
Step 500
500
#6186DC
oklch(63.2% 0.136 265.2)
-
Step 600
600
#486EC9
oklch(55.7% 0.147 265)
-
Step 700
700
#3A5BAE
oklch(49.1% 0.138 265.3)
-
Step 800
800 (this color)
#304B8D
oklch(42.8% 0.114 265.2)
-
Step 900
900
#2A3F70
oklch(37.6% 0.088 265)
-
Step 950
950
#192542
oklch(27% 0.057 265.8)
#304B8D 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) | #2B528F | 0.020 |
| Deuteranopia (no green cones) | #1B4A8C | 0.021 |
| Tritanopia (no blue cones) | #005A65 | 0.095 |
| Achromatopsia (no color) | #4E4E4E | 0.114 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #304B8D
#304B8D
oklch(42.8% 0.114 265.2)
- #654A00
#654A00
oklch(42.7% 0.087 84.5)
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 #304B8D, 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 0.023
- Light Navy #155084 ΔE 0.031
- Blueberry #464196 ΔE 0.041
- Deep Sea Blue #015482 ΔE 0.044
- Light Navy Blue #2E5A88 ΔE 0.046
- Twilight #4E518B ΔE 0.046
- Dark Slate Blue #483D8B ΔE 0.046
Use #304B8D 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.