#283F6B
Closest named color: Twilight Blue (#0A437A). oklch(37.2% 0.081 262.3), rgb(40, 63, 107).
Aa
White text reads best on this color (10.42:1).
About this color
#283F6B is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.081 and its hue 262°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.033 away. White text reads best on it, at 10.42:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.081) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.01:1 |
| White text | 10.42:1 |
Values
| HEX | #283F6B |
| RGB | rgb(40, 63, 107) |
| HSL | hsl(219, 46%, 29%) |
| OKLCH | oklch(37.2% 0.081 262.3) |
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 #283F6B | 10.42:1 | AAA | Lc -98.1 | Preferred for body text |
| Black text on #283F6B | 2.01:1 | Fails | Lc 9.9 | Not readable |
| #283F6B text on white | 10.42:1 | AAA | Lc 94.0 | Preferred for body text |
| #283F6B text on black | 2.01:1 | Fails | Lc -8.5 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E4EAF6
oklch(93.6% 0.017 264.5)
-
Step 200
200
#CDDAF0
oklch(88.5% 0.033 261)
-
Step 300
300
#ACC1E9
oklch(80.9% 0.061 263.2)
-
Step 400
400
#7FA1DE
oklch(70.8% 0.098 261.7)
-
Step 500
500
#5F88D5
oklch(63.1% 0.125 262.1)
-
Step 600
600
#4670C2
oklch(55.5% 0.136 262.4)
-
Step 700
700
#385EA7
oklch(49.2% 0.125 262.1)
-
Step 800
800
#2E4D88
oklch(42.8% 0.105 262)
-
Step 900
900 (this color)
#283F6B
oklch(37.2% 0.081 262.3)
-
Step 950
950
#182640
oklch(27% 0.052 262)
#283F6B 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) | #2C436D | 0.014 |
| Deuteranopia (no green cones) | #233D6A | 0.009 |
| Tritanopia (no blue cones) | #00494F | 0.072 |
| Achromatopsia (no color) | #404040 | 0.081 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283F6B
#283F6B
oklch(37.2% 0.081 262.3)
- #543B00
#543B00
oklch(37.1% 0.076 81.7)
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 #283F6B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.033
- Dark Grey Blue #29465B ΔE 0.040
- Marine Blue #01386A ΔE 0.041
- Prussian Blue #1D3557 ΔE 0.047
- Charcoal #264653 ΔE 0.053
- Dark Blue Grey #1F3B4D ΔE 0.054
- Light Navy #155084 ΔE 0.059
- Cobalt #1E488F ΔE 0.062
Use #283F6B 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.