#243B83
Closest named color: Twilight Blue (#0A437A). oklch(37.8% 0.124 266.9), rgb(36, 59, 131).
Aa
White text reads best on this color (10.35:1).
About this color
#243B83 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.124 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.033 away. White text reads best on it, at 10.35:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.124) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.02:1 |
| White text | 10.35:1 |
Values
| HEX | #243B83 |
| RGB | rgb(36, 59, 131) |
| HSL | hsl(225, 57%, 33%) |
| OKLCH | oklch(37.8% 0.124 266.9) |
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 #243B83 | 10.35:1 | AAA | Lc -97.7 | Preferred for body text |
| Black text on #243B83 | 2.02:1 | Fails | Lc 10.3 | Not readable |
| #243B83 text on white | 10.35:1 | AAA | Lc 93.7 | Preferred for body text |
| #243B83 text on black | 2.02:1 | 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
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E2EAFD
oklch(93.7% 0.027 267.5)
-
Step 200
200
#CAD9FC
oklch(88.5% 0.051 267)
-
Step 300
300
#A5BFFE
oklch(80.8% 0.094 267)
-
Step 400
400
#769BFD
oklch(70.6% 0.15 266.9)
-
Step 500
500
#557FFB
oklch(63.1% 0.19 266.8)
-
Step 600
600
#3D64EA
oklch(55.5% 0.207 267)
-
Step 700
700
#3052CC
oklch(49.1% 0.193 266.9)
-
Step 800
800
#2844A5
oklch(42.7% 0.16 267)
-
Step 900
900 (this color)
#243B83
oklch(37.8% 0.124 266.9)
-
Step 950
950
#15234C
oklch(27% 0.078 266.9)
#243B83 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) | #074586 | 0.031 |
| Deuteranopia (no green cones) | #003C82 | 0.025 |
| Tritanopia (no blue cones) | #004C59 | 0.100 |
| Achromatopsia (no color) | #404040 | 0.125 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243B83
#243B83
oklch(37.8% 0.124 266.9)
- #543E00
#543E00
oklch(37.8% 0.077 85.9)
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 #243B83, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.033
- Cobalt #1E488F ΔE 0.039
- Marine Blue #01386A ΔE 0.053
- Dark Slate Blue #483D8B ΔE 0.055
- Light Navy #155084 ΔE 0.059
- Blueberry #464196 ΔE 0.061
- Sapphire #2138AB ΔE 0.066
- Dusk Blue #26538D ΔE 0.069
Use #243B83 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.