#28377F
Closest named color: Twilight Blue (#0A437A). oklch(36.9% 0.123 270.4), rgb(40, 55, 127).
Aa
White text reads best on this color (10.80:1).
About this color
#28377F is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.123 and its hue 270°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.040 away. White text reads best on it, at 10.80:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.123) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.94:1 |
| White text | 10.80:1 |
Values
| HEX | #28377F |
| RGB | rgb(40, 55, 127) |
| HSL | hsl(230, 52%, 33%) |
| OKLCH | oklch(36.9% 0.123 270.4) |
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 #28377F | 10.80:1 | AAA | Lc -98.6 | Preferred for body text |
| Black text on #28377F | 1.94:1 | Fails | Lc 9.2 | Not readable |
| #28377F text on white | 10.80:1 | AAA | Lc 94.7 | Preferred for body text |
| #28377F text on black | 1.94:1 | Fails | Lc -7.9 | 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
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E3E9FC
oklch(93.5% 0.027 271.9)
-
Step 200
200
#CCD8FC
oklch(88.5% 0.051 270.8)
-
Step 300
300
#AABEFD
oklch(80.9% 0.092 270.6)
-
Step 400
400
#7E9AFC
oklch(70.8% 0.147 270.3)
-
Step 500
500
#607DFA
oklch(63.2% 0.188 270.4)
-
Step 600
600
#4962E9
oklch(55.7% 0.205 270.3)
-
Step 700
700
#3B50CA
oklch(49.1% 0.19 270.3)
-
Step 800
800
#3142A3
oklch(42.6% 0.157 270.7)
-
Step 900
900 (this color)
#28377F
oklch(36.9% 0.123 270.4)
-
Step 950
950
#18224C
oklch(26.9% 0.079 270.3)
#28377F 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) | #004181 | 0.036 |
| Deuteranopia (no green cones) | #003A7E | 0.031 |
| Tritanopia (no blue cones) | #004855 | 0.101 |
| Achromatopsia (no color) | #3D3D3D | 0.123 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #28377F
#28377F
oklch(36.9% 0.123 270.4)
- #4F3D00
#4F3D00
oklch(36.9% 0.075 89.9)
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 #28377F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.040
- Marine Blue #01386A ΔE 0.050
- Cobalt #1E488F ΔE 0.051
- Dark Slate Blue #483D8B ΔE 0.057
- Blueberry #464196 ΔE 0.066
- Light Navy #155084 ΔE 0.070
- Marine #042E60 ΔE 0.071
- Prussian Blue #1D3557 ΔE 0.072
Use #28377F 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.