#283F87
Closest named color: Cobalt (#1E488F). oklch(39.2% 0.124 267.2), rgb(40, 63, 135).
Aa
White text reads best on this color (9.76:1).
About this color
#283F87 is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.124 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.027 away. White text reads best on it, at 9.76:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.124) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.15:1 |
| White text | 9.76:1 |
Values
| HEX | #283F87 |
| RGB | rgb(40, 63, 135) |
| HSL | hsl(225, 54%, 34%) |
| OKLCH | oklch(39.2% 0.124 267.2) |
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 #283F87 | 9.76:1 | AAA | Lc -96.5 | Preferred for body text |
| Black text on #283F87 | 2.15:1 | Fails | Lc 11.6 | Not readable |
| #283F87 text on white | 9.76:1 | AAA | Lc 92.3 | Preferred for body text |
| #283F87 text on black | 2.15:1 | Fails | Lc -10.1 | 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
#E2EAFD
oklch(93.7% 0.027 267.5)
-
Step 200
200
#CAD9FC
oklch(88.5% 0.051 267)
-
Step 300
300
#A6BFFD
oklch(80.8% 0.092 267.4)
-
Step 400
400
#779BFD
oklch(70.6% 0.149 267.3)
-
Step 500
500
#567FFB
oklch(63.1% 0.19 267.1)
-
Step 600
600
#3E64EA
oklch(55.6% 0.207 267.2)
-
Step 700
700
#3152CB
oklch(49.1% 0.191 267.1)
-
Step 800
800
#2944A4
oklch(42.7% 0.158 267.3)
-
Step 900
900 (this color)
#283F87
oklch(39.2% 0.124 267.2)
-
Step 950
950
#15234C
oklch(27% 0.078 266.9)
#283F87 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) | #12488A | 0.028 |
| Deuteranopia (no green cones) | #004086 | 0.028 |
| Tritanopia (no blue cones) | #00505C | 0.102 |
| Achromatopsia (no color) | #444444 | 0.124 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283F87
#283F87
oklch(39.2% 0.124 267.2)
- #584200
#584200
oklch(39.2% 0.08 87)
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 #283F87, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.027
- Twilight Blue #0A437A ΔE 0.035
- Dark Slate Blue #483D8B ΔE 0.046
- Light Navy #155084 ΔE 0.050
- Blueberry #464196 ΔE 0.050
- Dusk Blue #26538D ΔE 0.056
- Sapphire #2138AB ΔE 0.062
- Deep Sea Blue #015482 ΔE 0.063
Use #283F87 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.