#243C69
Closest named color: Marine Blue (#01386A). oklch(36.1% 0.084 261.9), rgb(36, 60, 105).
Aa
White text reads best on this color (10.90:1).
About this color
#243C69 is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.084 and its hue 262°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.032 away. White text reads best on it, at 10.90:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.084) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.92:1 |
| White text | 10.90:1 |
Values
| HEX | #243C69 |
| RGB | rgb(36, 60, 105) |
| HSL | hsl(219, 49%, 28%) |
| OKLCH | oklch(36.1% 0.084 261.9) |
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 #243C69 | 10.90:1 | AAA | Lc -99.0 | Preferred for body text |
| Black text on #243C69 | 1.92:1 | Fails | Lc 8.8 | Not readable |
| #243C69 text on white | 10.90:1 | AAA | Lc 95.1 | Preferred for body text |
| #243C69 text on black | 1.92:1 | Fails | Lc -7.6 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E3EAF6
oklch(93.5% 0.018 261.3)
-
Step 200
200
#CDDAF1
oklch(88.6% 0.035 262)
-
Step 300
300
#ABC1EA
oklch(80.8% 0.063 262.8)
-
Step 400
400
#7EA1E0
oklch(70.8% 0.101 261.8)
-
Step 500
500
#5D88D7
oklch(63.1% 0.129 261.7)
-
Step 600
600
#4470C4
oklch(55.6% 0.14 262)
-
Step 700
700
#365DA9
oklch(49% 0.13 262.2)
-
Step 800
800
#2D4D89
oklch(42.8% 0.107 261.8)
-
Step 900
900 (this color)
#243C69
oklch(36.1% 0.084 261.9)
-
Step 950
950
#182640
oklch(27% 0.052 262)
#243C69 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) | #28406B | 0.014 |
| Deuteranopia (no green cones) | #1E3A68 | 0.010 |
| Tritanopia (no blue cones) | #00464D | 0.071 |
| Achromatopsia (no color) | #3D3D3D | 0.084 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243C69
#243C69
oklch(36.1% 0.084 261.9)
- #513900
#513900
oklch(36.2% 0.075 82.1)
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 #243C69, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.032
- Twilight Blue #0A437A ΔE 0.035
- Prussian Blue #1D3557 ΔE 0.038
- Dark Grey Blue #29465B ΔE 0.045
- Dark Blue Grey #1F3B4D ΔE 0.050
- Charcoal #264653 ΔE 0.056
- Marine #042E60 ΔE 0.057
- Midnight Green #073B4C ΔE 0.059
Use #243C69 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.