#243A84
Closest named color: Twilight Blue (#0A437A). oklch(37.7% 0.127 267.4), rgb(36, 58, 132).
Aa
White text reads best on this color (10.42:1).
About this color
#243A84 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.127 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.036 away. White text reads best on it, at 10.42:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.127) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.01:1 |
| White text | 10.42:1 |
Values
| HEX | #243A84 |
| RGB | rgb(36, 58, 132) |
| HSL | hsl(226, 57%, 33%) |
| OKLCH | oklch(37.7% 0.127 267.4) |
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 #243A84 | 10.42:1 | AAA | Lc -97.9 | Preferred for body text |
| Black text on #243A84 | 2.01:1 | Fails | Lc 10.1 | Not readable |
| #243A84 text on white | 10.42:1 | AAA | Lc 93.8 | Preferred for body text |
| #243A84 text on black | 2.01:1 | Fails | Lc -8.7 | 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
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E2EAFD
oklch(93.7% 0.027 267.5)
-
Step 200
200
#CAD9FD
oklch(88.6% 0.052 267.4)
-
Step 300
300
#A5BFFF
oklch(80.9% 0.095 267.2)
-
Step 400
400
#779BFF
oklch(70.7% 0.152 267.5)
-
Step 500
500
#567EFE
oklch(63.2% 0.195 267.5)
-
Step 600
600
#3E63ED
oklch(55.6% 0.212 267.5)
-
Step 700
700
#3151CE
oklch(49.2% 0.196 267.4)
-
Step 800
800
#2843A7
oklch(42.7% 0.164 267.3)
-
Step 900
900 (this color)
#243A84
oklch(37.7% 0.127 267.4)
-
Step 950
950
#15234D
oklch(27% 0.08 267.1)
#243A84 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) | #004487 | 0.032 |
| Deuteranopia (no green cones) | #003B83 | 0.025 |
| Tritanopia (no blue cones) | #004C59 | 0.103 |
| Achromatopsia (no color) | #404040 | 0.127 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243A84
#243A84
oklch(37.7% 0.127 267.4)
- #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 #243A84, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.036
- Cobalt #1E488F ΔE 0.040
- Marine Blue #01386A ΔE 0.054
- Dark Slate Blue #483D8B ΔE 0.055
- Blueberry #464196 ΔE 0.061
- Light Navy #155084 ΔE 0.062
- Sapphire #2138AB ΔE 0.065
- Dusk Blue #26538D ΔE 0.071
Use #243A84 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.