#283B6C
Closest named color: Twilight Blue (#0A437A). oklch(36.3% 0.088 266.2), rgb(40, 59, 108).
Aa
White text reads best on this color (10.86:1).
About this color
#283B6C is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.088 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.035 away. White text reads best on it, at 10.86:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.088) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.93:1 |
| White text | 10.86:1 |
Values
| HEX | #283B6C |
| RGB | rgb(40, 59, 108) |
| HSL | hsl(223, 46%, 29%) |
| OKLCH | oklch(36.3% 0.088 266.2) |
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 #283B6C | 10.86:1 | AAA | Lc -98.9 | Preferred for body text |
| Black text on #283B6C | 1.93:1 | Fails | Lc 8.9 | Not readable |
| #283B6C text on white | 10.86:1 | AAA | Lc 95.0 | Preferred for body text |
| #283B6C text on black | 1.93:1 | Fails | Lc -7.6 | 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
#F3F5FC
oklch(97.1% 0.01 273.4)
-
Step 100
100
#E4EAF7
oklch(93.6% 0.019 266)
-
Step 200
200
#CED9F2
oklch(88.5% 0.036 266.7)
-
Step 300
300
#ADC0EC
oklch(80.8% 0.066 266.6)
-
Step 400
400
#829FE3
oklch(70.8% 0.105 266.1)
-
Step 500
500
#6385DB
oklch(63% 0.135 266.3)
-
Step 600
600
#4B6DC9
oklch(55.6% 0.148 266.4)
-
Step 700
700
#3C5BAD
oklch(49.1% 0.136 266)
-
Step 800
800
#324B8C
oklch(42.8% 0.112 266)
-
Step 900
900 (this color)
#283B6C
oklch(36.3% 0.088 266.2)
-
Step 950
950
#1A2542
oklch(27% 0.056 266.9)
#283B6C 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) | #25406E | 0.015 |
| Deuteranopia (no green cones) | #1B3A6B | 0.016 |
| Tritanopia (no blue cones) | #00464E | 0.077 |
| Achromatopsia (no color) | #3D3D3D | 0.088 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283B6C
#283B6C
oklch(36.3% 0.088 266.2)
- #4F3A00
#4F3A00
oklch(36.2% 0.074 85.7)
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 #283B6C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.035
- Marine Blue #01386A ΔE 0.035
- Prussian Blue #1D3557 ΔE 0.043
- Dark Grey Blue #29465B ΔE 0.051
- Dark Blue Grey #1F3B4D ΔE 0.057
- Marine #042E60 ΔE 0.060
- Charcoal #264653 ΔE 0.063
- Cobalt #1E488F ΔE 0.065
Use #283B6C 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.