#243C6D
Closest named color: Twilight Blue (#0A437A). oklch(36.4% 0.09 263), rgb(36, 60, 109).
Aa
White text reads best on this color (10.81:1).
About this color
#243C6D is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.090 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.031 away. White text reads best on it, at 10.81:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.090) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.94:1 |
| White text | 10.81:1 |
Values
| HEX | #243C6D |
| RGB | rgb(36, 60, 109) |
| HSL | hsl(220, 50%, 28%) |
| OKLCH | oklch(36.4% 0.09 263) |
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 #243C6D | 10.81:1 | AAA | Lc -98.8 | Preferred for body text |
| Black text on #243C6D | 1.94:1 | Fails | Lc 9.1 | Not readable |
| #243C6D text on white | 10.81:1 | AAA | Lc 94.8 | Preferred for body text |
| #243C6D text on black | 1.94:1 | Fails | Lc -7.8 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E3EAF7
oklch(93.6% 0.019 263)
-
Step 200
200
#CCDAF3
oklch(88.6% 0.038 262.1)
-
Step 300
300
#AAC1ED
oklch(80.9% 0.067 263.3)
-
Step 400
400
#7DA0E4
oklch(70.7% 0.108 263)
-
Step 500
500
#5C87DC
oklch(63.1% 0.137 262.8)
-
Step 600
600
#436FCA
oklch(55.7% 0.149 263)
-
Step 700
700
#345CAF
oklch(49.1% 0.14 262.9)
-
Step 800
800
#2C4C8D
oklch(42.8% 0.114 262.8)
-
Step 900
900 (this color)
#243C6D
oklch(36.4% 0.09 263)
-
Step 950
950
#172642
oklch(27.1% 0.056 262)
#243C6D 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) | #25416F | 0.015 |
| Deuteranopia (no green cones) | #1A3A6C | 0.013 |
| Tritanopia (no blue cones) | #00474F | 0.075 |
| Achromatopsia (no color) | #3D3D3D | 0.090 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243C6D
#243C6D
oklch(36.4% 0.09 263)
- #513A00
#513A00
oklch(36.5% 0.075 83.5)
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 #243C6D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.031
- Marine Blue #01386A ΔE 0.032
- Prussian Blue #1D3557 ΔE 0.043
- Dark Grey Blue #29465B ΔE 0.050
- Dark Blue Grey #1F3B4D ΔE 0.057
- Marine #042E60 ΔE 0.059
- Charcoal #264653 ΔE 0.062
- Cobalt #1E488F ΔE 0.063
Use #243C6D 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.