#243C7E
Closest named color: Twilight Blue (#0A437A). oklch(37.6% 0.116 266), rgb(36, 60, 126).
Aa
White text reads best on this color (10.38:1).
About this color
#243C7E is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.116 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.027 away. White text reads best on it, at 10.38:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.116) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.02:1 |
| White text | 10.38:1 |
Values
| HEX | #243C7E |
| RGB | rgb(36, 60, 126) |
| HSL | hsl(224, 56%, 32%) |
| OKLCH | oklch(37.6% 0.116 266) |
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 #243C7E | 10.38:1 | AAA | Lc -97.8 | Preferred for body text |
| Black text on #243C7E | 2.02:1 | Fails | Lc 10.1 | Not readable |
| #243C7E text on white | 10.38:1 | AAA | Lc 93.8 | Preferred for body text |
| #243C7E text on black | 2.02:1 | Fails | Lc -8.8 | 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
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E2EAFB
oklch(93.6% 0.025 265.6)
-
Step 200
200
#CAD9FA
oklch(88.5% 0.048 266)
-
Step 300
300
#A6C0FA
oklch(80.9% 0.087 265.8)
-
Step 400
400
#789DF7
oklch(70.8% 0.139 266)
-
Step 500
500
#5681F4
oklch(63.1% 0.178 266)
-
Step 600
600
#3D67E2
oklch(55.5% 0.193 266)
-
Step 700
700
#3055C5
oklch(49.1% 0.18 266)
-
Step 800
800
#28469F
oklch(42.6% 0.149 266.1)
-
Step 900
900 (this color)
#243C7E
oklch(37.6% 0.116 266)
-
Step 950
950
#15244A
oklch(27% 0.073 265.6)
#243C7E 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) | #154480 | 0.024 |
| Deuteranopia (no green cones) | #003C7D | 0.026 |
| Tritanopia (no blue cones) | #004C57 | 0.095 |
| Achromatopsia (no color) | #404040 | 0.116 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243C7E
#243C7E
oklch(37.6% 0.116 266)
- #543E00
#543E00
oklch(37.8% 0.077 85.9)
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 #243C7E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.027
- Cobalt #1E488F ΔE 0.041
- Marine Blue #01386A ΔE 0.047
- Light Navy #155084 ΔE 0.057
- Dark Slate Blue #483D8B ΔE 0.057
- Blueberry #464196 ΔE 0.065
- Dusk Blue #26538D ΔE 0.068
- Deep Sea Blue #015482 ΔE 0.069
Use #243C7E 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.