#243F74
Closest named color: Twilight Blue (#0A437A). oklch(37.6% 0.097 262.4), rgb(36, 63, 116).
Aa
White text reads best on this color (10.30:1).
About this color
#243F74 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.097 and its hue 262°. 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 10.30:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.097) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.03:1 |
| White text | 10.30:1 |
Values
| HEX | #243F74 |
| RGB | rgb(36, 63, 116) |
| HSL | hsl(220, 53%, 30%) |
| OKLCH | oklch(37.6% 0.097 262.4) |
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 #243F74 | 10.30:1 | AAA | Lc -97.7 | Preferred for body text |
| Black text on #243F74 | 2.03:1 | Fails | Lc 10.2 | Not readable |
| #243F74 text on white | 10.30:1 | AAA | Lc 93.7 | Preferred for body text |
| #243F74 text on black | 2.03:1 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EAF8
oklch(93.5% 0.021 261.8)
-
Step 200
200
#CBDAF5
oklch(88.6% 0.041 262.3)
-
Step 300
300
#A8C1F0
oklch(80.9% 0.072 262.9)
-
Step 400
400
#79A0E9
oklch(70.7% 0.116 262.3)
-
Step 500
500
#5786E2
oklch(63% 0.148 262.5)
-
Step 600
600
#3D6ED0
oklch(55.6% 0.161 262.4)
-
Step 700
700
#2F5BB4
oklch(49% 0.15 262.5)
-
Step 800
800
#284B92
oklch(42.7% 0.124 262.6)
-
Step 900
900 (this color)
#243F74
oklch(37.6% 0.097 262.4)
-
Step 950
950
#162544
oklch(26.9% 0.061 263.4)
#243F74 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) | #264476 | 0.015 |
| Deuteranopia (no green cones) | #193D73 | 0.013 |
| Tritanopia (no blue cones) | #004B53 | 0.080 |
| Achromatopsia (no color) | #404040 | 0.097 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243F74
#243F74
oklch(37.6% 0.097 262.4)
- #553C00
#553C00
oklch(37.4% 0.077 82.1)
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 #243F74, 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 0.049
- Light Navy #155084 ΔE 0.052
- Dark Grey Blue #29465B ΔE 0.053
- Prussian Blue #1D3557 ΔE 0.057
- Deep Sea Blue #015482 ΔE 0.062
- Dark Slate Blue #483D8B ΔE 0.066
Use #243F74 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.