#243A85
Closest named color: Twilight Blue (#0A437A). oklch(37.8% 0.129 267.5), rgb(36, 58, 133).
Aa
White text reads best on this color (10.40:1).
About this color
#243A85 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.129 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.037 away. White text reads best on it, at 10.40:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.129) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.01:1 |
| White text | 10.40:1 |
Values
| HEX | #243A85 |
| RGB | rgb(36, 58, 133) |
| HSL | hsl(226, 57%, 33%) |
| OKLCH | oklch(37.8% 0.129 267.5) |
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 #243A85 | 10.40:1 | AAA | Lc -97.8 | Preferred for body text |
| Black text on #243A85 | 2.01:1 | Fails | Lc 10.2 | Not readable |
| #243A85 text on white | 10.40:1 | AAA | Lc 93.7 | Preferred for body text |
| #243A85 text on black | 2.01:1 | 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
#F2F5FF
oklch(97.1% 0.014 272.7)
-
Step 100
100
#E2EAFD
oklch(93.7% 0.027 267.5)
-
Step 200
200
#C9D9FE
oklch(88.5% 0.054 266.8)
-
Step 300
300
#A6BFFF
oklch(80.9% 0.095 267.8)
-
Step 400
400
#779BFF
oklch(70.7% 0.152 267.5)
-
Step 500
500
#557EFF
oklch(63.2% 0.197 267.3)
-
Step 600
600
#3D62EE
oklch(55.5% 0.215 267.4)
-
Step 700
700
#3050D0
oklch(49.1% 0.2 267.4)
-
Step 800
800
#2843A8
oklch(42.8% 0.165 267.4)
-
Step 900
900 (this color)
#243A85
oklch(37.8% 0.129 267.5)
-
Step 950
950
#15234E
oklch(27.1% 0.081 267.2)
#243A85 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) | #004488 | 0.032 |
| Deuteranopia (no green cones) | #003C84 | 0.025 |
| Tritanopia (no blue cones) | #004C59 | 0.104 |
| Achromatopsia (no color) | #404040 | 0.129 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243A85
#243A85
oklch(37.8% 0.129 267.5)
- #533E00
#533E00
oklch(37.6% 0.077 86.9)
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 #243A85, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.037
- Cobalt #1E488F ΔE 0.040
- Dark Slate Blue #483D8B ΔE 0.055
- Marine Blue #01386A ΔE 0.056
- Blueberry #464196 ΔE 0.061
- Light Navy #155084 ΔE 0.062
- Sapphire #2138AB ΔE 0.063
- Dusk Blue #26538D ΔE 0.071
Use #243A85 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.