#283F51
Closest named color: Dark Blue Grey (#1F3B4D). oklch(35.7% 0.043 242.9), rgb(40, 63, 81).
Aa
White text reads best on this color (10.93:1).
About this color
#283F51 is a dark, muted blue. In OKLCH its lightness is 36%, its chroma 0.043 and its hue 243°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Blue Grey (#1F3B4D), ΔE 0.019 away. White text reads best on it, at 10.93:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | muted (0.043) |
| Temperature | cool |
| Nearest name | Dark Blue Grey (#1F3B4D) |
| Black text | 1.92:1 |
| White text | 10.93:1 |
Values
| HEX | #283F51 |
| RGB | rgb(40, 63, 81) |
| HSL | hsl(206, 34%, 24%) |
| OKLCH | oklch(35.7% 0.043 242.9) |
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 #283F51 | 10.93:1 | AAA | Lc -99.1 | Preferred for body text |
| Black text on #283F51 | 1.92:1 | Fails | Lc 8.6 | Not readable |
| #283F51 text on white | 10.93:1 | AAA | Lc 95.3 | Preferred for body text |
| #283F51 text on black | 1.92:1 | Fails | Lc -7.4 | 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
#F3F6F8
oklch(97.1% 0.004 236.5)
-
Step 100
100
#E5EBF0
oklch(93.7% 0.009 242.8)
-
Step 200
200
#D0DBE4
oklch(88.6% 0.017 242.5)
-
Step 300
300
#B0C4D4
oklch(81% 0.031 242.1)
-
Step 400
400
#85A5BE
oklch(70.7% 0.051 242)
-
Step 500
500
#668EAE
oklch(63% 0.066 243.2)
-
Step 600
600
#4D789A
oklch(55.5% 0.071 243.4)
-
Step 700
700
#3E6583
oklch(49.1% 0.066 242.8)
-
Step 800
800
#33536B
oklch(42.8% 0.055 242.1)
-
Step 900
900 (this color)
#283F51
oklch(35.7% 0.043 242.9)
-
Step 950
950
#1B2833
oklch(27% 0.027 244.6)
#283F51 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) | #373F52 | 0.021 |
| Deuteranopia (no green cones) | #323B51 | 0.018 |
| Tritanopia (no blue cones) | #164345 | 0.034 |
| Achromatopsia (no color) | #3D3D3D | 0.043 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #283F51
#283F51
oklch(35.7% 0.043 242.9)
- #4C3724
#4C3724
oklch(35.5% 0.043 62.9)
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 #283F51, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Blue Grey #1F3B4D ΔE 0.019
- Charcoal #264653 ΔE 0.022
- Dark Grey Blue #29465B ΔE 0.025
- Onyx #343A40 ΔE 0.032
- Midnight Green #073B4C ΔE 0.035
- Charcoal Grey #3C4142 ΔE 0.040
- Prussian Blue #1D3557 ΔE 0.041
- Gunmetal #293241 ΔE 0.045
Use #283F51 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.