#243F7C
Closest named color: Twilight Blue (#0A437A). oklch(38.2% 0.109 264), rgb(36, 63, 124).
Aa
White text reads best on this color (10.11:1).
About this color
#243F7C is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.109 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.021 away. White text reads best on it, at 10.11:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.109) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.07:1 |
| White text | 10.11:1 |
Values
| HEX | #243F7C |
| RGB | rgb(36, 63, 124) |
| HSL | hsl(222, 55%, 31%) |
| OKLCH | oklch(38.2% 0.109 264) |
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 #243F7C | 10.11:1 | AAA | Lc -97.3 | Preferred for body text |
| Black text on #243F7C | 2.07:1 | Fails | Lc 10.8 | Not readable |
| #243F7C text on white | 10.11:1 | AAA | Lc 93.2 | Preferred for body text |
| #243F7C text on black | 2.07:1 | Fails | Lc -9.3 | 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
#F2F6FD
oklch(97.2% 0.01 261.8)
-
Step 100
100
#E2EAFA
oklch(93.6% 0.023 264.5)
-
Step 200
200
#CADAF8
oklch(88.6% 0.045 263.1)
-
Step 300
300
#A6C1F6
oklch(81% 0.081 263.6)
-
Step 400
400
#779EF2
oklch(70.6% 0.131 264.4)
-
Step 500
500
#5484ED
oklch(63.1% 0.166 263.8)
-
Step 600
600
#3A6BDC
oklch(55.7% 0.181 263.8)
-
Step 700
700
#2D58BF
oklch(49.1% 0.169 264.1)
-
Step 800
800
#26499A
oklch(42.8% 0.139 263.9)
-
Step 900
900 (this color)
#243F7C
oklch(38.2% 0.109 264)
-
Step 950
950
#152548
oklch(27.1% 0.069 263.9)
#243F7C 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) | #1F467E | 0.020 |
| Deuteranopia (no green cones) | #0B3E7B | 0.021 |
| Tritanopia (no blue cones) | #004D57 | 0.088 |
| Achromatopsia (no color) | #424242 | 0.109 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243F7C
#243F7C
oklch(38.2% 0.109 264)
- #563E00
#563E00
oklch(38% 0.078 83.8)
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 #243F7C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.021
- Cobalt #1E488F ΔE 0.038
- Marine Blue #01386A ΔE 0.048
- Light Navy #155084 ΔE 0.049
- Dark Slate Blue #483D8B ΔE 0.058
- Deep Sea Blue #015482 ΔE 0.061
- Dusk Blue #26538D ΔE 0.062
- Blueberry #464196 ΔE 0.065
Use #243F7C 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.