#243A63
Closest named color: Prussian Blue (#1D3557). oklch(35.2% 0.077 261.9), rgb(36, 58, 99).
Aa
White text reads best on this color (11.28:1).
About this color
#243A63 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.077 and its hue 262°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.027 away. White text reads best on it, at 11.28:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.077) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.86:1 |
| White text | 11.28:1 |
Values
| HEX | #243A63 |
| RGB | rgb(36, 58, 99) |
| HSL | hsl(219, 47%, 26%) |
| OKLCH | oklch(35.2% 0.077 261.9) |
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 #243A63 | 11.28:1 | AAA | Lc -99.7 | Preferred for body text |
| Black text on #243A63 | 1.86:1 | Fails | Lc 8.0 | Not readable |
| #243A63 text on white | 11.28:1 | AAA | Lc 95.9 | Preferred for body text |
| #243A63 text on black | 1.86:1 | 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
#F3F6FB
oklch(97.2% 0.007 260.7)
-
Step 100
100
#E4EAF5
oklch(93.6% 0.016 262.8)
-
Step 200
200
#CEDAEF
oklch(88.6% 0.032 261.7)
-
Step 300
300
#ACC1E7
oklch(80.8% 0.059 262.3)
-
Step 400
400
#81A1DB
oklch(70.8% 0.093 262)
-
Step 500
500
#6188D1
oklch(63% 0.119 262.1)
-
Step 600
600
#4871BE
oklch(55.6% 0.129 261.9)
-
Step 700
700
#395EA4
oklch(49% 0.12 261.9)
-
Step 800
800
#304D85
oklch(42.7% 0.1 262.3)
-
Step 900
900 (this color)
#243A63
oklch(35.2% 0.077 261.9)
-
Step 950
950
#19263E
oklch(27% 0.049 262)
#243A63 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) | #283E65 | 0.014 |
| Deuteranopia (no green cones) | #203862 | 0.008 |
| Tritanopia (no blue cones) | #004349 | 0.067 |
| Achromatopsia (no color) | #3B3B3B | 0.077 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243A63
#243A63
oklch(35.2% 0.077 261.9)
- #4E3600
#4E3600
oklch(35.1% 0.073 81)
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 #243A63, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.027
- Marine Blue #01386A ΔE 0.031
- Dark Blue Grey #1F3B4D ΔE 0.041
- Twilight Blue #0A437A ΔE 0.045
- Dark Grey Blue #29465B ΔE 0.045
- Midnight Green #073B4C ΔE 0.051
- Marine #042E60 ΔE 0.051
- Charcoal #264653 ΔE 0.054
Use #243A63 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.