#283B99
Closest named color: Sapphire (#2138AB). oklch(39.9% 0.155 269.3), rgb(40, 59, 153).
Aa
White text reads best on this color (9.65:1).
About this color
#283B99 is a dark, vivid blue. In OKLCH its lightness is 40%, its chroma 0.155 and its hue 269°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.031 away. White text reads best on it, at 9.65:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | vivid (0.155) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.17:1 |
| White text | 9.65:1 |
Values
| HEX | #283B99 |
| RGB | rgb(40, 59, 153) |
| HSL | hsl(230, 59%, 38%) |
| OKLCH | oklch(39.9% 0.155 269.3) |
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 #283B99 | 9.65:1 | AAA | Lc -96.1 | Preferred for body text |
| Black text on #283B99 | 2.17:1 | Fails | Lc 12.1 | Not readable |
| #283B99 text on white | 9.65:1 | AAA | Lc 91.8 | Preferred for body text |
| #283B99 text on black | 2.17:1 | Fails | Lc -10.6 | 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
#E1EAFF
oklch(93.7% 0.03 267.2)
-
Step 200
200
#CAD8FF
oklch(88.4% 0.056 269.7)
-
Step 300
300
#A8BEFF
oklch(80.9% 0.096 269.8)
-
Step 400
400
#7B9AFF
oklch(70.8% 0.152 269.4)
-
Step 500
500
#5B7CFF
oklch(63.1% 0.198 269.4)
-
Step 600
600
#3F5AFF
oklch(55.6% 0.244 269.2)
-
Step 700
700
#3244E5
oklch(49.1% 0.239 269.4)
-
Step 800
800
#283AB9
oklch(42.7% 0.198 269.2)
-
Step 900
900 (this color)
#283B99
oklch(39.9% 0.155 269.3)
-
Step 950
950
#142055
oklch(27% 0.097 269.2)
#283B99 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) | #004A9C | 0.041 |
| Deuteranopia (no green cones) | #003F97 | 0.027 |
| Tritanopia (no blue cones) | #005364 | 0.124 |
| Achromatopsia (no color) | #454545 | 0.155 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283B99
#283B99
oklch(39.9% 0.155 269.3)
- #594400
#594400
oklch(39.8% 0.081 88.6)
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 #283B99, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.031
- Cobalt #1E488F ΔE 0.039
- Blueberry #464196 ΔE 0.047
- Dark Slate Blue #483D8B ΔE 0.053
- Twilight Blue #0A437A ΔE 0.062
- Indigo Blue #3A18B1 ΔE 0.069
- Dusk Blue #26538D ΔE 0.070
- Light Navy #155084 ΔE 0.070
Use #283B99 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.