#283F6F
Closest named color: Twilight Blue (#0A437A). oklch(37.5% 0.087 263.5), rgb(40, 63, 111).
Aa
White text reads best on this color (10.34:1).
About this color
#283F6F is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.087 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.028 away. White text reads best on it, at 10.34:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.087) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.03:1 |
| White text | 10.34:1 |
Values
| HEX | #283F6F |
| RGB | rgb(40, 63, 111) |
| HSL | hsl(221, 47%, 30%) |
| OKLCH | oklch(37.5% 0.087 263.5) |
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 #283F6F | 10.34:1 | AAA | Lc -97.9 | Preferred for body text |
| Black text on #283F6F | 2.03:1 | Fails | Lc 10.1 | Not readable |
| #283F6F text on white | 10.34:1 | AAA | Lc 93.8 | Preferred for body text |
| #283F6F text on black | 2.03:1 | Fails | Lc -8.7 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E3EAF7
oklch(93.6% 0.019 263)
-
Step 200
200
#CDDAF2
oklch(88.6% 0.036 262.8)
-
Step 300
300
#ABC1EC
oklch(80.9% 0.066 263.7)
-
Step 400
400
#7EA0E2
oklch(70.7% 0.104 263.1)
-
Step 500
500
#5E87DA
oklch(63.1% 0.134 263.2)
-
Step 600
600
#456FC8
oklch(55.7% 0.146 263.4)
-
Step 700
700
#375CAD
oklch(49.1% 0.136 263.7)
-
Step 800
800
#2E4C8C
oklch(42.8% 0.112 263.5)
-
Step 900
900 (this color)
#283F6F
oklch(37.5% 0.087 263.5)
-
Step 950
950
#182641
oklch(27.1% 0.054 262.5)
#283F6F 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) | #2A4471 | 0.016 |
| Deuteranopia (no green cones) | #203D6E | 0.012 |
| Tritanopia (no blue cones) | #004A51 | 0.076 |
| Achromatopsia (no color) | #404040 | 0.088 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283F6F
#283F6F
oklch(37.5% 0.087 263.5)
- #543C00
#543C00
oklch(37.3% 0.077 83.1)
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 #283F6F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.028
- Marine Blue #01386A ΔE 0.042
- Dark Grey Blue #29465B ΔE 0.046
- Prussian Blue #1D3557 ΔE 0.052
- Light Navy #155084 ΔE 0.056
- Cobalt #1E488F ΔE 0.056
- Charcoal #264653 ΔE 0.059
- Dark Blue Grey #1F3B4D ΔE 0.061
Use #283F6F 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.