#243C61
Closest named color: Prussian Blue (#1D3557). oklch(35.6% 0.071 258.8), rgb(36, 60, 97).
Aa
White text reads best on this color (11.08:1).
About this color
#243C61 is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.071 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.028 away. White text reads best on it, at 11.08:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.071) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.89:1 |
| White text | 11.08:1 |
Values
| HEX | #243C61 |
| RGB | rgb(36, 60, 97) |
| HSL | hsl(216, 46%, 26%) |
| OKLCH | oklch(35.6% 0.071 258.8) |
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 #243C61 | 11.08:1 | AAA | Lc -99.3 | Preferred for body text |
| Black text on #243C61 | 1.89:1 | Fails | Lc 8.4 | Not readable |
| #243C61 text on white | 11.08:1 | AAA | Lc 95.5 | Preferred for body text |
| #243C61 text on black | 1.89:1 | Fails | Lc 0.0 | 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
#F3F6FA
oklch(97.2% 0.006 255.5)
-
Step 100
100
#E4EAF4
oklch(93.5% 0.015 260.7)
-
Step 200
200
#CEDAED
oklch(88.5% 0.029 259.6)
-
Step 300
300
#ACC2E4
oklch(80.9% 0.054 259)
-
Step 400
400
#80A2D6
oklch(70.7% 0.085 258.7)
-
Step 500
500
#608ACB
oklch(63.1% 0.109 258.9)
-
Step 600
600
#4673B8
oklch(55.6% 0.119 258.7)
-
Step 700
700
#38609F
oklch(49.1% 0.111 259.1)
-
Step 800
800
#2E4F81
oklch(42.8% 0.092 258.5)
-
Step 900
900 (this color)
#243C61
oklch(35.6% 0.071 258.8)
-
Step 950
950
#19273C
oklch(27.1% 0.044 258.3)
#243C61 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) | #2D3F63 | 0.016 |
| Deuteranopia (no green cones) | #253960 | 0.009 |
| Tritanopia (no blue cones) | #00444A | 0.061 |
| Achromatopsia (no color) | #3C3C3C | 0.071 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243C61
#243C61
oklch(35.6% 0.071 258.8)
- #503704
#503704
oklch(35.7% 0.071 79)
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 #243C61, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.028
- Marine Blue #01386A ΔE 0.036
- Dark Blue Grey #1F3B4D ΔE 0.036
- Dark Grey Blue #29465B ΔE 0.038
- Twilight Blue #0A437A ΔE 0.046
- Charcoal #264653 ΔE 0.046
- Midnight Green #073B4C ΔE 0.047
- Marine #042E60 ΔE 0.056
Use #243C61 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.