#283F7B
Closest named color: Twilight Blue (#0A437A). oklch(38.3% 0.106 265.8), rgb(40, 63, 123).
Aa
White text reads best on this color (10.06:1).
About this color
#283F7B is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.106 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.025 away. White text reads best on it, at 10.06:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.106) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.08:1 |
| White text | 10.06:1 |
Values
| HEX | #283F7B |
| RGB | rgb(40, 63, 123) |
| HSL | hsl(223, 51%, 32%) |
| OKLCH | oklch(38.3% 0.106 265.8) |
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 #283F7B | 10.06:1 | AAA | Lc -97.2 | Preferred for body text |
| Black text on #283F7B | 2.08:1 | Fails | Lc 10.8 | Not readable |
| #283F7B text on white | 10.06:1 | AAA | Lc 93.1 | Preferred for body text |
| #283F7B text on black | 2.08:1 | Fails | Lc -9.4 | 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
#F2F5FD
oklch(97% 0.011 269.6)
-
Step 100
100
#E3EAFA
oklch(93.6% 0.023 266.9)
-
Step 200
200
#CBD9F7
oklch(88.4% 0.044 265.6)
-
Step 300
300
#A8C0F5
oklch(80.9% 0.08 265.7)
-
Step 400
400
#7B9EF0
oklch(70.8% 0.127 265.7)
-
Step 500
500
#5A83EB
oklch(63.1% 0.163 265.8)
-
Step 600
600
#426AD9
oklch(55.6% 0.176 265.9)
-
Step 700
700
#3458BC
oklch(49.2% 0.163 265.7)
-
Step 800
800
#2B4898
oklch(42.6% 0.136 265.8)
-
Step 900
900 (this color)
#283F7B
oklch(38.3% 0.106 265.8)
-
Step 950
950
#172447
oklch(26.9% 0.068 266.6)
#283F7B 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) | #21467D | 0.020 |
| Deuteranopia (no green cones) | #113E7A | 0.022 |
| Tritanopia (no blue cones) | #004D57 | 0.088 |
| Achromatopsia (no color) | #424242 | 0.106 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283F7B
#283F7B
oklch(38.3% 0.106 265.8)
- #563F00
#563F00
oklch(38.3% 0.078 85.1)
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 #283F7B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.025
- Cobalt #1E488F ΔE 0.039
- Light Navy #155084 ΔE 0.049
- Marine Blue #01386A ΔE 0.050
- Dark Slate Blue #483D8B ΔE 0.054
- Dusk Blue #26538D ΔE 0.061
- Deep Sea Blue #015482 ΔE 0.061
- Blueberry #464196 ΔE 0.063
Use #283F7B 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.