#243D84
Closest named color: Twilight Blue (#0A437A). oklch(38.3% 0.123 266.1), rgb(36, 61, 132).
Aa
White text reads best on this color (10.11:1).
About this color
#243D84 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.123 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.031 away. White text reads best on it, at 10.11:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.123) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.07:1 |
| White text | 10.11:1 |
Values
| HEX | #243D84 |
| RGB | rgb(36, 61, 132) |
| HSL | hsl(224, 57%, 33%) |
| OKLCH | oklch(38.3% 0.123 266.1) |
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 #243D84 | 10.11:1 | AAA | Lc -97.3 | Preferred for body text |
| Black text on #243D84 | 2.07:1 | Fails | Lc 10.8 | Not readable |
| #243D84 text on white | 10.11:1 | AAA | Lc 93.1 | Preferred for body text |
| #243D84 text on black | 2.07:1 | Fails | Lc -9.4 | 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
#F1F5FE
oklch(97% 0.013 266.7)
-
Step 100
100
#E1EAFC
oklch(93.6% 0.026 264.4)
-
Step 200
200
#C9D9FC
oklch(88.5% 0.051 265.9)
-
Step 300
300
#A5C0FD
oklch(81% 0.092 265.9)
-
Step 400
400
#759CFC
oklch(70.6% 0.147 266)
-
Step 500
500
#5380FA
oklch(63.1% 0.189 265.9)
-
Step 600
600
#3A65E9
oklch(55.5% 0.205 266.1)
-
Step 700
700
#2D53CB
oklch(49.1% 0.191 266)
-
Step 800
800
#2645A4
oklch(42.8% 0.158 266.1)
-
Step 900
900 (this color)
#243D84
oklch(38.3% 0.123 266.1)
-
Step 950
950
#14234C
oklch(26.9% 0.078 266.1)
#243D84 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) | #0E4687 | 0.027 |
| Deuteranopia (no green cones) | #003D83 | 0.025 |
| Tritanopia (no blue cones) | #004E5A | 0.100 |
| Achromatopsia (no color) | #424242 | 0.123 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243D84
#243D84
oklch(38.3% 0.123 266.1)
- #563F00
#563F00
oklch(38.3% 0.078 85.1)
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 #243D84, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.031
- Cobalt #1E488F ΔE 0.033
- Dark Slate Blue #483D8B ΔE 0.053
- Light Navy #155084 ΔE 0.054
- Marine Blue #01386A ΔE 0.056
- Blueberry #464196 ΔE 0.058
- Dusk Blue #26538D ΔE 0.063
- Sapphire #2138AB ΔE 0.066
Use #243D84 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.