#283F5B
Closest named color: Dark Grey Blue (#29465B). oklch(36.2% 0.057 254), rgb(40, 63, 91).
Aa
White text reads best on this color (10.75:1).
About this color
#283F5B is a dark, muted blue. In OKLCH its lightness is 36%, its chroma 0.057 and its hue 254°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.023 away. White text reads best on it, at 10.75:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | muted (0.057) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 1.95:1 |
| White text | 10.75:1 |
Values
| HEX | #283F5B |
| RGB | rgb(40, 63, 91) |
| HSL | hsl(213, 39%, 26%) |
| OKLCH | oklch(36.2% 0.057 254) |
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 #283F5B | 10.75:1 | AAA | Lc -98.8 | Preferred for body text |
| Black text on #283F5B | 1.95:1 | Fails | Lc 9.1 | Not readable |
| #283F5B text on white | 10.75:1 | AAA | Lc 94.8 | Preferred for body text |
| #283F5B text on black | 1.95:1 | Fails | Lc -7.8 | 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
#F3F6F9
oklch(97.2% 0.005 247.9)
-
Step 100
100
#E4EAF2
oklch(93.5% 0.013 255.5)
-
Step 200
200
#CFDAE9
oklch(88.5% 0.024 256.1)
-
Step 300
300
#AEC3DC
oklch(80.9% 0.042 252.9)
-
Step 400
400
#83A3CB
oklch(70.6% 0.069 254.3)
-
Step 500
500
#648CBD
oklch(63.1% 0.087 254)
-
Step 600
600
#4B76AA
oklch(55.8% 0.094 254)
-
Step 700
700
#3C6392
oklch(49.3% 0.088 254)
-
Step 800
800
#325176
oklch(42.8% 0.072 253.7)
-
Step 900
900 (this color)
#283F5B
oklch(36.2% 0.057 254)
-
Step 950
950
#1A2738
oklch(26.9% 0.037 255.4)
#283F5B 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) | #34405C | 0.017 |
| Deuteranopia (no green cones) | #2D3B5A | 0.013 |
| Tritanopia (no blue cones) | #0D4549 | 0.049 |
| Achromatopsia (no color) | #3E3E3E | 0.057 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283F5B
#283F5B
oklch(36.2% 0.057 254)
- #4F3919
#4F3919
oklch(36.2% 0.056 74.6)
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 #283F5B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.023
- Dark Blue Grey #1F3B4D ΔE 0.029
- Charcoal #264653 ΔE 0.030
- Prussian Blue #1D3557 ΔE 0.036
- Midnight Green #073B4C ΔE 0.043
- Onyx #343A40 ΔE 0.047
- Marine Blue #01386A ΔE 0.050
- Charcoal Grey #3C4142 ΔE 0.053
Use #283F5B 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.