#243E8E
Closest named color: Cobalt (#1E488F). oklch(39.4% 0.136 266.5), rgb(36, 62, 142).
Aa
White text reads best on this color (9.74:1).
About this color
#243E8E is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.136 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.027 away. White text reads best on it, at 9.74:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.136) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.15:1 |
| White text | 9.74:1 |
Values
| HEX | #243E8E |
| RGB | rgb(36, 62, 142) |
| HSL | hsl(225, 60%, 35%) |
| OKLCH | oklch(39.4% 0.136 266.5) |
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 #243E8E | 9.74:1 | AAA | Lc -96.4 | Preferred for body text |
| Black text on #243E8E | 2.15:1 | Fails | Lc 11.8 | Not readable |
| #243E8E text on white | 9.74:1 | AAA | Lc 92.2 | Preferred for body text |
| #243E8E text on black | 2.15:1 | Fails | Lc -10.2 | 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
#F1F5FF
oklch(97% 0.014 268.5)
-
Step 100
100
#E1EAFE
oklch(93.6% 0.029 266.4)
-
Step 200
200
#C8D9FF
oklch(88.5% 0.056 266.2)
-
Step 300
300
#A4BFFF
oklch(80.8% 0.096 266.6)
-
Step 400
400
#759CFF
oklch(70.8% 0.151 266.4)
-
Step 500
500
#527EFF
oklch(63% 0.198 266.5)
-
Step 600
600
#3661F6
oklch(55.7% 0.228 266.4)
-
Step 700
700
#2A4ED6
oklch(49% 0.212 266.5)
-
Step 800
800
#2341AD
oklch(42.6% 0.176 266.6)
-
Step 900
900 (this color)
#243E8E
oklch(39.4% 0.136 266.5)
-
Step 950
950
#132250
oklch(26.9% 0.087 266.8)
#243E8E 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) | #004991 | 0.033 |
| Deuteranopia (no green cones) | #003F8C | 0.024 |
| Tritanopia (no blue cones) | #00525F | 0.111 |
| Achromatopsia (no color) | #444444 | 0.137 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243E8E
#243E8E
oklch(39.4% 0.136 266.5)
- #594200
#594200
oklch(39.3% 0.081 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 #243E8E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.027
- Twilight Blue #0A437A ΔE 0.042
- Sapphire #2138AB ΔE 0.050
- Blueberry #464196 ΔE 0.050
- Dark Slate Blue #483D8B ΔE 0.050
- Light Navy #155084 ΔE 0.055
- Dusk Blue #26538D ΔE 0.060
- Deep Sea Blue #015482 ΔE 0.069
Use #243E8E 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.