#243C80
Closest named color: Twilight Blue (#0A437A). oklch(37.8% 0.119 266.2), rgb(36, 60, 128).
Aa
White text reads best on this color (10.32:1).
About this color
#243C80 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.119 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.029 away. White text reads best on it, at 10.32:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.119) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.03:1 |
| White text | 10.32:1 |
Values
| HEX | #243C80 |
| RGB | rgb(36, 60, 128) |
| HSL | hsl(224, 56%, 32%) |
| OKLCH | oklch(37.8% 0.119 266.2) |
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 #243C80 | 10.32:1 | AAA | Lc -97.7 | Preferred for body text |
| Black text on #243C80 | 2.03:1 | Fails | Lc 10.3 | Not readable |
| #243C80 text on white | 10.32:1 | AAA | Lc 93.6 | Preferred for body text |
| #243C80 text on black | 2.03:1 | Fails | Lc -8.9 | 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
#E2EAFC
oklch(93.6% 0.026 266.6)
-
Step 200
200
#CAD9FB
oklch(88.5% 0.05 266.5)
-
Step 300
300
#A6C0FB
oklch(81% 0.089 266)
-
Step 400
400
#779CF9
oklch(70.6% 0.143 266.4)
-
Step 500
500
#5681F6
oklch(63.2% 0.181 266.2)
-
Step 600
600
#3D66E5
oklch(55.5% 0.198 266.4)
-
Step 700
700
#3054C7
oklch(49.1% 0.184 266.3)
-
Step 800
800
#2846A1
oklch(42.8% 0.152 266.2)
-
Step 900
900 (this color)
#243C80
oklch(37.8% 0.119 266.2)
-
Step 950
950
#15244B
oklch(27.1% 0.075 265.8)
#243C80 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) | #124582 | 0.027 |
| Deuteranopia (no green cones) | #003C7F | 0.025 |
| Tritanopia (no blue cones) | #004C58 | 0.096 |
| Achromatopsia (no color) | #404040 | 0.119 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243C80
#243C80
oklch(37.8% 0.119 266.2)
- #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 #243C80, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.029
- Cobalt #1E488F ΔE 0.039
- Marine Blue #01386A ΔE 0.050
- Dark Slate Blue #483D8B ΔE 0.056
- Light Navy #155084 ΔE 0.057
- Blueberry #464196 ΔE 0.063
- Dusk Blue #26538D ΔE 0.067
- Deep Sea Blue #015482 ΔE 0.069
Use #243C80 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.