#243F57
Closest named color: Dark Blue Grey (#1F3B4D). oklch(35.8% 0.053 246.8), rgb(36, 63, 87).
Aa
White text reads best on this color (10.91:1).
About this color
#243F57 is a dark, muted blue. In OKLCH its lightness is 36%, its chroma 0.053 and its hue 247°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Blue Grey (#1F3B4D), ΔE 0.021 away. White text reads best on it, at 10.91:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | muted (0.053) |
| Temperature | cool |
| Nearest name | Dark Blue Grey (#1F3B4D) |
| Black text | 1.92:1 |
| White text | 10.91:1 |
Values
| HEX | #243F57 |
| RGB | rgb(36, 63, 87) |
| HSL | hsl(208, 41%, 24%) |
| OKLCH | oklch(35.8% 0.053 246.8) |
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 #243F57 | 10.91:1 | AAA | Lc -99.0 | Preferred for body text |
| Black text on #243F57 | 1.92:1 | Fails | Lc 8.7 | Not readable |
| #243F57 text on white | 10.91:1 | AAA | Lc 95.2 | Preferred for body text |
| #243F57 text on black | 1.92:1 | Fails | Lc -7.5 | 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
#E4EBF1
oklch(93.6% 0.011 243.7)
-
Step 200
200
#CEDBE7
oklch(88.5% 0.022 245.9)
-
Step 300
300
#ACC4DA
oklch(80.9% 0.041 246)
-
Step 400
400
#80A5C7
oklch(70.7% 0.064 246.6)
-
Step 500
500
#5F8EB9
oklch(63% 0.083 247.1)
-
Step 600
600
#4578A5
oklch(55.7% 0.089 246.8)
-
Step 700
700
#36658D
oklch(49.2% 0.083 246.2)
-
Step 800
800
#2E5272
oklch(42.6% 0.068 247)
-
Step 900
900 (this color)
#243F57
oklch(35.8% 0.053 246.8)
-
Step 950
950
#182836
oklch(27% 0.034 245.9)
#243F57 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) | #354058 | 0.023 |
| Deuteranopia (no green cones) | #2E3A57 | 0.019 |
| Tritanopia (no blue cones) | #044547 | 0.046 |
| Achromatopsia (no color) | #3D3D3D | 0.053 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243F57
#243F57
oklch(35.8% 0.053 246.8)
- #4F371C
#4F371C
oklch(35.8% 0.053 67.9)
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 #243F57, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Blue Grey #1F3B4D ΔE 0.021
- Dark Grey Blue #29465B ΔE 0.024
- Charcoal #264653 ΔE 0.027
- Prussian Blue #1D3557 ΔE 0.035
- Midnight Green #073B4C ΔE 0.035
- Onyx #343A40 ΔE 0.042
- Gunmetal #293241 ΔE 0.049
- Charcoal Grey #3C4142 ΔE 0.050
Use #243F57 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.