#28307B
Closest named color: Marine Blue (#01386A). oklch(35.1% 0.126 273.4), rgb(40, 48, 123).
Aa
White text reads best on this color (11.67:1).
About this color
#28307B is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.126 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.049 away. White text reads best on it, at 11.67:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.126) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.79:1 |
| White text | 11.67:1 |
Values
| HEX | #28307B |
| RGB | rgb(40, 48, 123) |
| HSL | hsl(234, 51%, 32%) |
| OKLCH | oklch(35.1% 0.126 273.4) |
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 #28307B | 11.67:1 | AAA | Lc -100.1 | Preferred for body text |
| Black text on #28307B | 1.79:1 | Fails | Lc 7.4 | Not readable |
| #28307B text on white | 11.67:1 | AAA | Lc 96.4 | Preferred for body text |
| #28307B text on black | 1.79:1 | Fails | Lc 0.0 | 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
#E4E9FD
oklch(93.6% 0.028 274.7)
-
Step 200
200
#CDD8FD
oklch(88.6% 0.052 272.2)
-
Step 300
300
#ACBDFE
oklch(80.9% 0.094 272.8)
-
Step 400
400
#8397FE
oklch(70.6% 0.152 273.6)
-
Step 500
500
#677AFC
oklch(63.2% 0.193 273.3)
-
Step 600
600
#515EEB
oklch(55.5% 0.21 273.4)
-
Step 700
700
#424CCD
oklch(49% 0.197 273.2)
-
Step 800
800
#3640A6
oklch(42.8% 0.162 273.1)
-
Step 900
900 (this color)
#28307B
oklch(35.1% 0.126 273.4)
-
Step 950
950
#1B214D
oklch(27% 0.081 273.9)
#28307B 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) | #003C7E | 0.040 |
| Deuteranopia (no green cones) | #00357A | 0.034 |
| Tritanopia (no blue cones) | #004250 | 0.105 |
| Achromatopsia (no color) | #383838 | 0.127 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #28307B
#28307B
oklch(35.1% 0.126 273.4)
- #473900
#473900
oklch(34.9% 0.072 93.4)
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 #28307B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.049
- Twilight Blue #0A437A ΔE 0.055
- Marine #042E60 ΔE 0.061
- Midnight Blue #191970 ΔE 0.065
- Prussian Blue #1D3557 ΔE 0.068
- Dark Slate Blue #483D8B ΔE 0.069
- Cobalt #1E488F ΔE 0.070
- Royal #0C1793 ΔE 0.074
Use #28307B 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.