#283F5F
Closest named color: Dark Grey Blue (#29465B). oklch(36.5% 0.063 256.8), rgb(40, 63, 95).
Aa
White text reads best on this color (10.67:1).
About this color
#283F5F is a dark, muted blue. In OKLCH its lightness is 36%, its chroma 0.063 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.026 away. White text reads best on it, at 10.67:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | muted (0.063) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 1.96:1 |
| White text | 10.67:1 |
Values
| HEX | #283F5F |
| RGB | rgb(40, 63, 95) |
| HSL | hsl(215, 41%, 26%) |
| OKLCH | oklch(36.5% 0.063 256.8) |
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 #283F5F | 10.67:1 | AAA | Lc -98.6 | Preferred for body text |
| Black text on #283F5F | 1.96:1 | Fails | Lc 9.3 | Not readable |
| #283F5F text on white | 10.67:1 | AAA | Lc 94.7 | Preferred for body text |
| #283F5F text on black | 1.96:1 | Fails | Lc -7.9 | 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
#F3F6FA
oklch(97.2% 0.006 255.5)
-
Step 100
100
#E4EAF3
oklch(93.5% 0.014 258.3)
-
Step 200
200
#CEDAEB
oklch(88.4% 0.027 257)
-
Step 300
300
#AEC2DF
oklch(80.8% 0.047 257.6)
-
Step 400
400
#82A3D0
oklch(70.8% 0.076 256.3)
-
Step 500
500
#638BC3
oklch(63.1% 0.096 256.9)
-
Step 600
600
#4974B0
oklch(55.5% 0.106 256.9)
-
Step 700
700
#3B6197
oklch(49% 0.097 257.3)
-
Step 800
800
#31507B
oklch(42.8% 0.081 256.8)
-
Step 900
900 (this color)
#283F5F
oklch(36.5% 0.063 256.8)
-
Step 950
950
#1A273A
oklch(27% 0.04 257.8)
#283F5F 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) | #324160 | 0.016 |
| Deuteranopia (no green cones) | #2B3C5E | 0.009 |
| Tritanopia (no blue cones) | #08464A | 0.056 |
| Achromatopsia (no color) | #3E3E3E | 0.063 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283F5F
#283F5F
oklch(36.5% 0.063 256.8)
- #513913
#513913
oklch(36.4% 0.063 75.7)
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 #283F5F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.026
- Dark Blue Grey #1F3B4D ΔE 0.035
- Charcoal #264653 ΔE 0.035
- Prussian Blue #1D3557 ΔE 0.037
- Marine Blue #01386A ΔE 0.047
- Midnight Green #073B4C ΔE 0.048
- Twilight Blue #0A437A ΔE 0.049
- Onyx #343A40 ΔE 0.053
Use #283F5F 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.