#243F6C
Closest named color: Twilight Blue (#0A437A). oklch(37% 0.085 260.1), rgb(36, 63, 108).
Aa
White text reads best on this color (10.48:1).
About this color
#243F6C is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.085 and its hue 260°. 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 10.48:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.085) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.00:1 |
| White text | 10.48:1 |
Values
| HEX | #243F6C |
| RGB | rgb(36, 63, 108) |
| HSL | hsl(218, 50%, 28%) |
| OKLCH | oklch(37% 0.085 260.1) |
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 #243F6C | 10.48:1 | AAA | Lc -98.1 | Preferred for body text |
| Black text on #243F6C | 2.00:1 | Fails | Lc 9.8 | Not readable |
| #243F6C text on white | 10.48:1 | AAA | Lc 94.1 | Preferred for body text |
| #243F6C text on black | 2.00:1 | Fails | Lc -8.4 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E3EAF6
oklch(93.5% 0.018 261.3)
-
Step 200
200
#CCDAF1
oklch(88.5% 0.035 260.4)
-
Step 300
300
#A9C2EA
oklch(80.9% 0.063 259.7)
-
Step 400
400
#7BA1E0
oklch(70.6% 0.102 260.2)
-
Step 500
500
#5989D7
oklch(63.1% 0.129 259.7)
-
Step 600
600
#3F71C5
oklch(55.6% 0.142 260.1)
-
Step 700
700
#315EAA
oklch(49.1% 0.132 260.2)
-
Step 800
800
#294D8A
oklch(42.6% 0.11 260.3)
-
Step 900
900 (this color)
#243F6C
oklch(37% 0.085 260.1)
-
Step 950
950
#162640
oklch(26.9% 0.053 259.7)
#243F6C 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) | #2B436E | 0.016 |
| Deuteranopia (no green cones) | #213C6B | 0.010 |
| Tritanopia (no blue cones) | #004950 | 0.070 |
| Achromatopsia (no color) | #3F3F3F | 0.085 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243F6C
#243F6C
oklch(37% 0.085 260.1)
- #553A00
#553A00
oklch(37% 0.077 79.3)
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 #243F6C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.029
- Marine Blue #01386A ΔE 0.037
- Dark Grey Blue #29465B ΔE 0.042
- Prussian Blue #1D3557 ΔE 0.046
- Charcoal #264653 ΔE 0.054
- Dark Blue Grey #1F3B4D ΔE 0.055
- Light Navy #155084 ΔE 0.058
- Cobalt #1E488F ΔE 0.061
Use #243F6C 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.