#283F71
Closest named color: Twilight Blue (#0A437A). oklch(37.6% 0.091 264), rgb(40, 63, 113).
Aa
White text reads best on this color (10.29:1).
About this color
#283F71 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.091 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.027 away. White text reads best on it, at 10.29:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.091) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.03:1 |
| White text | 10.29:1 |
Values
| HEX | #283F71 |
| RGB | rgb(40, 63, 113) |
| HSL | hsl(221, 48%, 30%) |
| OKLCH | oklch(37.6% 0.091 264) |
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 #283F71 | 10.29:1 | AAA | Lc -97.8 | Preferred for body text |
| Black text on #283F71 | 2.03:1 | Fails | Lc 10.2 | Not readable |
| #283F71 text on white | 10.29:1 | AAA | Lc 93.7 | Preferred for body text |
| #283F71 text on black | 2.03:1 | Fails | Lc -8.8 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E3EAF7
oklch(93.6% 0.019 263)
-
Step 200
200
#CDDAF3
oklch(88.6% 0.037 263.6)
-
Step 300
300
#AAC1ED
oklch(80.9% 0.067 263.3)
-
Step 400
400
#7EA0E5
oklch(70.8% 0.108 263.8)
-
Step 500
500
#5E86DD
oklch(63.1% 0.139 264.2)
-
Step 600
600
#446ECB
oklch(55.6% 0.152 263.9)
-
Step 700
700
#365BAF
oklch(49% 0.141 264)
-
Step 800
800
#2D4B8E
oklch(42.7% 0.117 264)
-
Step 900
900 (this color)
#283F71
oklch(37.6% 0.091 264)
-
Step 950
950
#182542
oklch(26.9% 0.057 264.6)
#283F71 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) | #294473 | 0.015 |
| Deuteranopia (no green cones) | #1E3D70 | 0.014 |
| Tritanopia (no blue cones) | #004A52 | 0.077 |
| Achromatopsia (no color) | #404040 | 0.091 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283F71
#283F71
oklch(37.6% 0.091 264)
- #543D00
#543D00
oklch(37.5% 0.077 84.5)
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 #283F71, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.027
- Marine Blue #01386A ΔE 0.043
- Dark Grey Blue #29465B ΔE 0.049
- Cobalt #1E488F ΔE 0.053
- Prussian Blue #1D3557 ΔE 0.054
- Light Navy #155084 ΔE 0.054
- Charcoal #264653 ΔE 0.062
- Deep Sea Blue #015482 ΔE 0.064
Use #283F71 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.