#283C5B
Closest named color: Prussian Blue (#1D3557). oklch(35.5% 0.06 258.9), rgb(40, 60, 91).
Aa
White text reads best on this color (11.12:1).
About this color
#283C5B is a dark, muted blue. In OKLCH its lightness is 35%, its chroma 0.060 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.028 away. White text reads best on it, at 11.12:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | muted (0.060) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.88:1 |
| White text | 11.12:1 |
Values
| HEX | #283C5B |
| RGB | rgb(40, 60, 91) |
| HSL | hsl(216, 39%, 26%) |
| OKLCH | oklch(35.5% 0.06 258.9) |
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 #283C5B | 11.12:1 | AAA | Lc -99.4 | Preferred for body text |
| Black text on #283C5B | 1.88:1 | Fails | Lc 8.3 | Not readable |
| #283C5B text on white | 11.12:1 | AAA | Lc 95.6 | Preferred for body text |
| #283C5B text on black | 1.88:1 | Fails | Lc 0.0 | 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
#F3F6FA
oklch(97.2% 0.006 255.5)
-
Step 100
100
#E5EAF3
oklch(93.6% 0.013 262.4)
-
Step 200
200
#CFDAEA
oklch(88.5% 0.025 257.6)
-
Step 300
300
#AFC2DE
oklch(80.9% 0.045 258)
-
Step 400
400
#86A2CE
oklch(70.7% 0.072 259.3)
-
Step 500
500
#678AC1
oklch(63% 0.092 259.2)
-
Step 600
600
#4E74AE
oklch(55.7% 0.101 258.6)
-
Step 700
700
#3F6195
oklch(49.1% 0.093 258.6)
-
Step 800
800
#344F79
oklch(42.6% 0.078 258.9)
-
Step 900
900 (this color)
#283C5B
oklch(35.5% 0.06 258.9)
-
Step 950
950
#1B2739
oklch(27.1% 0.038 258.3)
#283C5B 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) | #303E5C | 0.013 |
| Deuteranopia (no green cones) | #2A395A | 0.009 |
| Tritanopia (no blue cones) | #0E4347 | 0.054 |
| Achromatopsia (no color) | #3B3B3B | 0.060 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283C5B
#283C5B
oklch(35.5% 0.06 258.9)
- #4D3812
#4D3812
oklch(35.6% 0.061 79.2)
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 #283C5B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.028
- Dark Blue Grey #1F3B4D ΔE 0.028
- Dark Grey Blue #29465B ΔE 0.033
- Charcoal #264653 ΔE 0.039
- Midnight Green #073B4C ΔE 0.042
- Marine Blue #01386A ΔE 0.045
- Onyx #343A40 ΔE 0.048
- Gunmetal #293241 ΔE 0.050
Use #283C5B 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.