#243F6F
Closest named color: Twilight Blue (#0A437A). oklch(37.2% 0.089 261), rgb(36, 63, 111).
Aa
White text reads best on this color (10.41:1).
About this color
#243F6F is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.089 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.025 away. White text reads best on it, at 10.41:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.089) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.01:1 |
| White text | 10.41:1 |
Values
| HEX | #243F6F |
| RGB | rgb(36, 63, 111) |
| HSL | hsl(218, 51%, 29%) |
| OKLCH | oklch(37.2% 0.089 261) |
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 #243F6F | 10.41:1 | AAA | Lc -98.0 | Preferred for body text |
| Black text on #243F6F | 2.01:1 | Fails | Lc 10.0 | Not readable |
| #243F6F text on white | 10.41:1 | AAA | Lc 94.0 | Preferred for body text |
| #243F6F text on black | 2.01:1 | Fails | Lc -8.6 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E3EAF7
oklch(93.6% 0.019 263)
-
Step 200
200
#CCDAF2
oklch(88.5% 0.036 261.3)
-
Step 300
300
#A9C2ED
oklch(81% 0.067 261.2)
-
Step 400
400
#7AA1E3
oklch(70.7% 0.106 260.6)
-
Step 500
500
#5988DB
oklch(63.1% 0.136 261)
-
Step 600
600
#3E70C9
oklch(55.6% 0.148 261)
-
Step 700
700
#305DAE
oklch(49.1% 0.139 261.1)
-
Step 800
800
#294C8D
oklch(42.6% 0.115 261.5)
-
Step 900
900 (this color)
#243F6F
oklch(37.2% 0.089 261)
-
Step 950
950
#162642
oklch(27% 0.057 260.9)
#243F6F 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) | #294371 | 0.014 |
| Deuteranopia (no green cones) | #1E3C6E | 0.012 |
| Tritanopia (no blue cones) | #004A51 | 0.075 |
| Achromatopsia (no color) | #404040 | 0.089 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243F6F
#243F6F
oklch(37.2% 0.089 261)
- #553B00
#553B00
oklch(37.2% 0.077 80.7)
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 #243F6F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.025
- Marine Blue #01386A ΔE 0.038
- Dark Grey Blue #29465B ΔE 0.046
- Prussian Blue #1D3557 ΔE 0.050
- Light Navy #155084 ΔE 0.056
- Cobalt #1E488F ΔE 0.056
- Charcoal #264653 ΔE 0.059
- Dark Blue Grey #1F3B4D ΔE 0.060
Use #243F6F 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.