#283B9C
Closest named color: Sapphire (#2138AB). oklch(40.2% 0.159 269.3), rgb(40, 59, 156).
Aa
White text reads best on this color (9.56:1).
About this color
#283B9C is a dark, vivid blue. In OKLCH its lightness is 40%, its chroma 0.159 and its hue 269°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.026 away. White text reads best on it, at 9.56:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | vivid (0.159) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.19:1 |
| White text | 9.56:1 |
Values
| HEX | #283B9C |
| RGB | rgb(40, 59, 156) |
| HSL | hsl(230, 59%, 38%) |
| OKLCH | oklch(40.2% 0.159 269.3) |
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 #283B9C | 9.56:1 | AAA | Lc -95.9 | Preferred for body text |
| Black text on #283B9C | 2.19:1 | Fails | Lc 12.4 | Not readable |
| #283B9C text on white | 9.56:1 | AAA | Lc 91.6 | Preferred for body text |
| #283B9C text on black | 2.19:1 | Fails | Lc -10.8 | 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
#3142E9
oklch(49.2% 0.246 269.3)
-
Step 800
800
#2838BC
oklch(42.7% 0.204 269.4)
-
Step 900
900 (this color)
#283B9C
oklch(40.2% 0.159 269.3)
-
Step 950
950
#141F57
oklch(27% 0.102 269.7)
#283B9C 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) | #004B9F | 0.043 |
| Deuteranopia (no green cones) | #00409A | 0.027 |
| Tritanopia (no blue cones) | #005465 | 0.127 |
| Achromatopsia (no color) | #454545 | 0.159 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283B9C
#283B9C
oklch(40.2% 0.159 269.3)
- #5A4500
#5A4500
oklch(40.2% 0.082 88.8)
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 #283B9C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.026
- Cobalt #1E488F ΔE 0.041
- Blueberry #464196 ΔE 0.048
- Dark Slate Blue #483D8B ΔE 0.055
- Twilight Blue #0A437A ΔE 0.066
- Indigo Blue #3A18B1 ΔE 0.067
- Dusk Blue #26538D ΔE 0.071
- Blue Blue #2242C7 ΔE 0.071
Use #283B9C 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.