#243C5D
Closest named color: Prussian Blue (#1D3557). oklch(35.3% 0.065 256.6), rgb(36, 60, 93).
Aa
White text reads best on this color (11.17:1).
About this color
#243C5D is a dark, muted blue. In OKLCH its lightness is 35%, its chroma 0.065 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.026 away. White text reads best on it, at 11.17:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | muted (0.065) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.87:1 |
| White text | 11.17:1 |
Values
| HEX | #243C5D |
| RGB | rgb(36, 60, 93) |
| HSL | hsl(215, 44%, 25%) |
| OKLCH | oklch(35.3% 0.065 256.6) |
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 #243C5D | 11.17:1 | AAA | Lc -99.5 | Preferred for body text |
| Black text on #243C5D | 1.87:1 | Fails | Lc 8.2 | Not readable |
| #243C5D text on white | 11.17:1 | AAA | Lc 95.7 | Preferred for body text |
| #243C5D text on black | 1.87:1 | 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
#E4EAF3
oklch(93.5% 0.014 258.3)
-
Step 200
200
#CEDAEB
oklch(88.4% 0.027 257)
-
Step 300
300
#ADC2E1
oklch(80.8% 0.05 258)
-
Step 400
400
#81A3D1
oklch(70.7% 0.078 256.1)
-
Step 500
500
#618BC5
oklch(63% 0.1 256.6)
-
Step 600
600
#4774B2
oklch(55.5% 0.109 256.7)
-
Step 700
700
#396199
oklch(49% 0.101 257.1)
-
Step 800
800
#2F507C
oklch(42.8% 0.083 256.1)
-
Step 900
900 (this color)
#243C5D
oklch(35.3% 0.065 256.6)
-
Step 950
950
#19273A
oklch(27% 0.041 256.3)
#243C5D 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) | #2E3E5E | 0.015 |
| Deuteranopia (no green cones) | #27395C | 0.009 |
| Tritanopia (no blue cones) | #004348 | 0.056 |
| Achromatopsia (no color) | #3B3B3B | 0.065 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243C5D
#243C5D
oklch(35.3% 0.065 256.6)
- #4E360C
#4E360C
oklch(35.2% 0.065 77)
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 #243C5D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.026
- Dark Blue Grey #1F3B4D ΔE 0.029
- Dark Grey Blue #29465B ΔE 0.035
- Marine Blue #01386A ΔE 0.039
- Midnight Green #073B4C ΔE 0.041
- Charcoal #264653 ΔE 0.042
- Twilight Blue #0A437A ΔE 0.052
- Gunmetal #293241 ΔE 0.052
Use #243C5D 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.