#283F73
Closest named color: Twilight Blue (#0A437A). oklch(37.7% 0.094 264.4), rgb(40, 63, 115).
Aa
White text reads best on this color (10.24:1).
About this color
#283F73 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.094 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.026 away. White text reads best on it, at 10.24:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.094) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.04:1 |
| White text | 10.24:1 |
Values
| HEX | #283F73 |
| RGB | rgb(40, 63, 115) |
| HSL | hsl(222, 48%, 30%) |
| OKLCH | oklch(37.7% 0.094 264.4) |
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 #283F73 | 10.24:1 | AAA | Lc -97.7 | Preferred for body text |
| Black text on #283F73 | 2.04:1 | Fails | Lc 10.3 | Not readable |
| #283F73 text on white | 10.24:1 | AAA | Lc 93.6 | Preferred for body text |
| #283F73 text on black | 2.04:1 | Fails | Lc -8.9 | 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
#F2F5FC
oklch(97% 0.01 267.4)
-
Step 100
100
#E3EAF8
oklch(93.6% 0.02 264.5)
-
Step 200
200
#CCD9F4
oklch(88.4% 0.04 265.1)
-
Step 300
300
#AAC1EF
oklch(81% 0.07 264.1)
-
Step 400
400
#7D9FE7
oklch(70.7% 0.113 264.4)
-
Step 500
500
#5D86E0
oklch(63.2% 0.143 264.2)
-
Step 600
600
#446DCE
oklch(55.6% 0.157 264.6)
-
Step 700
700
#365BB2
oklch(49.2% 0.145 264.4)
-
Step 800
800
#2D4B90
oklch(42.8% 0.119 264.3)
-
Step 900
900 (this color)
#283F73
oklch(37.7% 0.094 264.4)
-
Step 950
950
#182543
oklch(27% 0.059 265)
#283F73 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) | #274475 | 0.015 |
| Deuteranopia (no green cones) | #1C3E72 | 0.014 |
| Tritanopia (no blue cones) | #004B53 | 0.080 |
| Achromatopsia (no color) | #414141 | 0.094 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283F73
#283F73
oklch(37.7% 0.094 264.4)
- #553D00
#553D00
oklch(37.7% 0.077 83.5)
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 #283F73, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.026
- Marine Blue #01386A ΔE 0.044
- Cobalt #1E488F ΔE 0.050
- Dark Grey Blue #29465B ΔE 0.052
- Light Navy #155084 ΔE 0.053
- Prussian Blue #1D3557 ΔE 0.057
- Dark Slate Blue #483D8B ΔE 0.063
- Deep Sea Blue #015482 ΔE 0.063
Use #283F73 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.