#243C86
Closest named color: Cobalt (#1E488F). oklch(38.3% 0.128 266.7), rgb(36, 60, 134).
Aa
White text reads best on this color (10.16:1).
About this color
#243C86 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.128 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.034 away. White text reads best on it, at 10.16:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.06:1 |
| White text | 10.16:1 |
Values
| HEX | #243C86 |
| RGB | rgb(36, 60, 134) |
| HSL | hsl(225, 58%, 33%) |
| OKLCH | oklch(38.3% 0.128 266.7) |
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 #243C86 | 10.16:1 | AAA | Lc -97.3 | Preferred for body text |
| Black text on #243C86 | 2.06:1 | Fails | Lc 10.7 | Not readable |
| #243C86 text on white | 10.16:1 | AAA | Lc 93.2 | Preferred for body text |
| #243C86 text on black | 2.06:1 | Fails | Lc -9.3 | 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
#F1F5FE
oklch(97% 0.013 266.7)
-
Step 100
100
#E1EAFD
oklch(93.6% 0.028 265.4)
-
Step 200
200
#C9D9FD
oklch(88.5% 0.053 266.4)
-
Step 300
300
#A5BFFF
oklch(80.9% 0.095 267.2)
-
Step 400
400
#759BFF
oklch(70.6% 0.153 266.8)
-
Step 500
500
#537EFE
oklch(63% 0.196 266.7)
-
Step 600
600
#3B63ED
oklch(55.5% 0.213 266.8)
-
Step 700
700
#2E51CF
oklch(49.1% 0.198 266.7)
-
Step 800
800
#2643A7
oklch(42.6% 0.164 266.7)
-
Step 900
900 (this color)
#243C86
oklch(38.3% 0.128 266.7)
-
Step 950
950
#14234D
oklch(27% 0.08 266.3)
#243C86 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) | #054689 | 0.031 |
| Deuteranopia (no green cones) | #003D85 | 0.024 |
| Tritanopia (no blue cones) | #004E5B | 0.102 |
| Achromatopsia (no color) | #414141 | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243C86
#243C86
oklch(38.3% 0.128 266.7)
- #554000
#554000
oklch(38.4% 0.078 87.5)
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 #243C86, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.034
- Twilight Blue #0A437A ΔE 0.034
- Dark Slate Blue #483D8B ΔE 0.053
- Light Navy #155084 ΔE 0.057
- Blueberry #464196 ΔE 0.058
- Marine Blue #01386A ΔE 0.058
- Sapphire #2138AB ΔE 0.062
- Dusk Blue #26538D ΔE 0.066
Use #243C86 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.