#283C89
Closest named color: Cobalt (#1E488F). oklch(38.7% 0.131 268.6), rgb(40, 60, 137).
Aa
White text reads best on this color (10.01:1).
About this color
#283C89 is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.131 and its hue 269°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.033 away. White text reads best on it, at 10.01:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.131) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.09:1 |
| White text | 10.01:1 |
Values
| HEX | #283C89 |
| RGB | rgb(40, 60, 137) |
| HSL | hsl(228, 55%, 35%) |
| OKLCH | oklch(38.7% 0.131 268.6) |
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 #283C89 | 10.01:1 | AAA | Lc -97.0 | Preferred for body text |
| Black text on #283C89 | 2.09:1 | Fails | Lc 11.1 | Not readable |
| #283C89 text on white | 10.01:1 | AAA | Lc 92.9 | Preferred for body text |
| #283C89 text on black | 2.09:1 | 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
#F2F5FF
oklch(97.1% 0.014 272.7)
-
Step 100
100
#E2EAFE
oklch(93.7% 0.028 268.4)
-
Step 200
200
#CAD9FE
oklch(88.6% 0.054 267.9)
-
Step 300
300
#A7BFFF
oklch(81% 0.095 268.4)
-
Step 400
400
#799AFF
oklch(70.6% 0.153 268.6)
-
Step 500
500
#597DFF
oklch(63.2% 0.197 268.6)
-
Step 600
600
#4161F0
oklch(55.7% 0.217 268.6)
-
Step 700
700
#344FD1
oklch(49.2% 0.202 268.6)
-
Step 800
800
#2B41A9
oklch(42.6% 0.168 268.8)
-
Step 900
900 (this color)
#283C89
oklch(38.7% 0.131 268.6)
-
Step 950
950
#16224E
oklch(26.9% 0.083 268.8)
#283C89 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) | #00478C | 0.035 |
| Deuteranopia (no green cones) | #003E87 | 0.029 |
| Tritanopia (no blue cones) | #004F5C | 0.107 |
| Achromatopsia (no color) | #424242 | 0.131 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283C89
#283C89
oklch(38.7% 0.131 268.6)
- #564100
#564100
oklch(38.7% 0.079 87.8)
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 #283C89, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.033
- Twilight Blue #0A437A ΔE 0.040
- Dark Slate Blue #483D8B ΔE 0.048
- Blueberry #464196 ΔE 0.051
- Sapphire #2138AB ΔE 0.057
- Light Navy #155084 ΔE 0.058
- Dusk Blue #26538D ΔE 0.064
- Marine Blue #01386A ΔE 0.065
Use #283C89 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.