#243A74
Closest named color: Twilight Blue (#0A437A). oklch(36.4% 0.103 265.9), rgb(36, 58, 116).
Aa
White text reads best on this color (10.86:1).
About this color
#243A74 is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.103 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.030 away. White text reads best on it, at 10.86:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.103) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.93:1 |
| White text | 10.86:1 |
Values
| HEX | #243A74 |
| RGB | rgb(36, 58, 116) |
| HSL | hsl(224, 53%, 30%) |
| OKLCH | oklch(36.4% 0.103 265.9) |
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 #243A74 | 10.86:1 | AAA | Lc -98.8 | Preferred for body text |
| Black text on #243A74 | 1.93:1 | Fails | Lc 9.0 | Not readable |
| #243A74 text on white | 10.86:1 | AAA | Lc 94.9 | Preferred for body text |
| #243A74 text on black | 1.93:1 | Fails | Lc -7.7 | 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
#F2F5FD
oklch(97% 0.011 269.6)
-
Step 100
100
#E3EAF9
oklch(93.6% 0.022 265.8)
-
Step 200
200
#CCD9F7
oklch(88.5% 0.044 266.9)
-
Step 300
300
#A9C0F4
oklch(80.9% 0.078 266.1)
-
Step 400
400
#7C9EEE
oklch(70.7% 0.124 265.8)
-
Step 500
500
#5C83E9
oklch(63.1% 0.159 266.2)
-
Step 600
600
#436AD7
oklch(55.5% 0.173 266.1)
-
Step 700
700
#3558BA
oklch(49.1% 0.16 265.9)
-
Step 800
800
#2C4997
oklch(42.8% 0.133 265.7)
-
Step 900
900 (this color)
#243A74
oklch(36.4% 0.103 265.9)
-
Step 950
950
#172446
oklch(26.9% 0.066 266.3)
#243A74 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) | #1C4176 | 0.020 |
| Deuteranopia (no green cones) | #0A3A73 | 0.022 |
| Tritanopia (no blue cones) | #004751 | 0.085 |
| Achromatopsia (no color) | #3D3D3D | 0.103 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243A74
#243A74
oklch(36.4% 0.103 265.9)
- #503B00
#503B00
oklch(36.6% 0.075 86)
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 #243A74, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.030
- Marine Blue #01386A ΔE 0.035
- Prussian Blue #1D3557 ΔE 0.053
- Cobalt #1E488F ΔE 0.056
- Marine #042E60 ΔE 0.060
- Dark Grey Blue #29465B ΔE 0.064
- Light Navy #155084 ΔE 0.065
- Dark Slate Blue #483D8B ΔE 0.068
Use #243A74 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.