#243F75
Closest named color: Twilight Blue (#0A437A). oklch(37.7% 0.098 262.6), rgb(36, 63, 117).
Aa
White text reads best on this color (10.27:1).
About this color
#243F75 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.098 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.021 away. White text reads best on it, at 10.27:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.098) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.04:1 |
| White text | 10.27:1 |
Values
| HEX | #243F75 |
| RGB | rgb(36, 63, 117) |
| HSL | hsl(220, 53%, 30%) |
| OKLCH | oklch(37.7% 0.098 262.6) |
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 #243F75 | 10.27:1 | AAA | Lc -97.7 | Preferred for body text |
| Black text on #243F75 | 2.04:1 | Fails | Lc 10.3 | Not readable |
| #243F75 text on white | 10.27:1 | AAA | Lc 93.6 | Preferred for body text |
| #243F75 text on black | 2.04:1 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EAF9
oklch(93.5% 0.022 263.2)
-
Step 200
200
#CBDAF5
oklch(88.6% 0.041 262.3)
-
Step 300
300
#A7C1F1
oklch(80.8% 0.074 262.5)
-
Step 400
400
#79A0EA
oklch(70.8% 0.117 262.5)
-
Step 500
500
#5786E4
oklch(63.1% 0.151 262.8)
-
Step 600
600
#3C6ED2
oklch(55.7% 0.164 262.4)
-
Step 700
700
#2F5BB6
oklch(49.2% 0.153 262.7)
-
Step 800
800
#274B93
oklch(42.7% 0.126 262.4)
-
Step 900
900 (this color)
#243F75
oklch(37.7% 0.098 262.6)
-
Step 950
950
#152545
oklch(26.9% 0.064 262.8)
#243F75 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) | #254577 | 0.018 |
| Deuteranopia (no green cones) | #173D74 | 0.015 |
| Tritanopia (no blue cones) | #004B54 | 0.080 |
| Achromatopsia (no color) | #414141 | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243F75
#243F75
oklch(37.7% 0.098 262.6)
- #553D00
#553D00
oklch(37.7% 0.077 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 #243F75, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.021
- Marine Blue #01386A ΔE 0.041
- Cobalt #1E488F ΔE 0.047
- Light Navy #155084 ΔE 0.052
- Dark Grey Blue #29465B ΔE 0.055
- Prussian Blue #1D3557 ΔE 0.058
- Deep Sea Blue #015482 ΔE 0.062
- Dark Slate Blue #483D8B ΔE 0.064
Use #243F75 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.