#243B6B
Closest named color: Marine Blue (#01386A). oklch(36% 0.088 263.3), rgb(36, 59, 107).
Aa
White text reads best on this color (10.97:1).
About this color
#243B6B is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.088 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.031 away. White text reads best on it, at 10.97:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.088) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.91:1 |
| White text | 10.97:1 |
Values
| HEX | #243B6B |
| RGB | rgb(36, 59, 107) |
| HSL | hsl(221, 50%, 28%) |
| OKLCH | oklch(36% 0.088 263.3) |
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 #243B6B | 10.97:1 | AAA | Lc -99.1 | Preferred for body text |
| Black text on #243B6B | 1.91:1 | Fails | Lc 8.7 | Not readable |
| #243B6B text on white | 10.97:1 | AAA | Lc 95.2 | Preferred for body text |
| #243B6B text on black | 1.91:1 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E3EAF7
oklch(93.6% 0.019 263)
-
Step 200
200
#CDDAF2
oklch(88.6% 0.036 262.8)
-
Step 300
300
#ABC1EC
oklch(80.9% 0.066 263.7)
-
Step 400
400
#7EA0E3
oklch(70.7% 0.106 263.3)
-
Step 500
500
#5E87DB
oklch(63.2% 0.135 263.4)
-
Step 600
600
#446FC8
oklch(55.6% 0.146 263.1)
-
Step 700
700
#365CAD
oklch(49% 0.137 263.3)
-
Step 800
800
#2D4C8C
oklch(42.8% 0.112 263)
-
Step 900
900 (this color)
#243B6B
oklch(36% 0.088 263.3)
-
Step 950
950
#182642
oklch(27.2% 0.056 263.1)
#243B6B 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) | #25406D | 0.015 |
| Deuteranopia (no green cones) | #1A396A | 0.013 |
| Tritanopia (no blue cones) | #00464D | 0.075 |
| Achromatopsia (no color) | #3C3C3C | 0.088 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243B6B
#243B6B
oklch(36% 0.088 263.3)
- #503900
#503900
oklch(36.1% 0.074 83.2)
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 #243B6B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.031
- Twilight Blue #0A437A ΔE 0.034
- Prussian Blue #1D3557 ΔE 0.039
- Dark Grey Blue #29465B ΔE 0.050
- Dark Blue Grey #1F3B4D ΔE 0.054
- Marine #042E60 ΔE 0.056
- Charcoal #264653 ΔE 0.061
- Midnight Green #073B4C ΔE 0.063
Use #243B6B 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.