#243F7A
Closest named color: Twilight Blue (#0A437A). oklch(38% 0.106 263.7), rgb(36, 63, 122).
Aa
White text reads best on this color (10.15:1).
About this color
#243F7A is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.106 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 10.15:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.106) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.06:1 |
| White text | 10.15:1 |
Values
| HEX | #243F7A |
| RGB | rgb(36, 63, 122) |
| HSL | hsl(221, 54%, 31%) |
| OKLCH | oklch(38% 0.106 263.7) |
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 #243F7A | 10.15:1 | AAA | Lc -97.4 | Preferred for body text |
| Black text on #243F7A | 2.06:1 | Fails | Lc 10.6 | Not readable |
| #243F7A text on white | 10.15:1 | AAA | Lc 93.3 | Preferred for body text |
| #243F7A text on black | 2.06:1 | Fails | Lc -9.2 | 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
#CADAF7
oklch(88.5% 0.044 262.4)
-
Step 300
300
#A6C1F5
oklch(80.9% 0.08 263.3)
-
Step 400
400
#779FF0
oklch(70.7% 0.127 263.5)
-
Step 500
500
#5584EA
oklch(63% 0.162 263.8)
-
Step 600
600
#3B6BD9
oklch(55.5% 0.177 263.8)
-
Step 700
700
#2D59BC
oklch(49.1% 0.164 263.5)
-
Step 800
800
#264998
oklch(42.6% 0.136 263.7)
-
Step 900
900 (this color)
#243F7A
oklch(38% 0.106 263.7)
-
Step 950
950
#152547
oklch(27.1% 0.067 263.6)
#243F7A 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) | #21467C | 0.020 |
| Deuteranopia (no green cones) | #0F3E79 | 0.019 |
| Tritanopia (no blue cones) | #004D56 | 0.087 |
| Achromatopsia (no color) | #414141 | 0.106 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243F7A
#243F7A
oklch(38% 0.106 263.7)
- #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 #243F7A, 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 0.040
- Marine Blue #01386A ΔE 0.046
- Light Navy #155084 ΔE 0.049
- Dark Slate Blue #483D8B ΔE 0.059
- Deep Sea Blue #015482 ΔE 0.061
- Dark Grey Blue #29465B ΔE 0.062
- Dusk Blue #26538D ΔE 0.063
Use #243F7A 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.