#243D9A
Closest named color: Sapphire (#2138AB). oklch(40.2% 0.155 267.4), rgb(36, 61, 154).
Aa
White text reads best on this color (9.50:1).
About this color
#243D9A is a dark, vivid blue. In OKLCH its lightness is 40%, its chroma 0.155 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.030 away. White text reads best on it, at 9.50:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | vivid (0.155) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.20:1 |
| White text | 9.50:1 |
Values
| HEX | #243D9A |
| RGB | rgb(36, 61, 154) |
| HSL | hsl(227, 62%, 37%) |
| OKLCH | oklch(40.2% 0.155 267.4) |
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 #243D9A | 9.50:1 | AAA | Lc -95.8 | Preferred for body text |
| Black text on #243D9A | 2.20:1 | Fails | Lc 12.5 | Not readable |
| #243D9A text on white | 9.50:1 | AAA | Lc 91.5 | Preferred for body text |
| #243D9A text on black | 2.20:1 | Fails | Lc -10.9 | 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
#F1F5FF
oklch(97% 0.014 268.5)
-
Step 100
100
#E1EAFF
oklch(93.7% 0.03 267.2)
-
Step 200
200
#C9D9FF
oklch(88.6% 0.055 267.2)
-
Step 300
300
#A5BFFF
oklch(80.9% 0.095 267.2)
-
Step 400
400
#779BFF
oklch(70.7% 0.152 267.5)
-
Step 500
500
#557EFF
oklch(63.2% 0.197 267.3)
-
Step 600
600
#375CFF
oklch(55.6% 0.244 267.4)
-
Step 700
700
#2946E5
oklch(49.1% 0.239 267.4)
-
Step 800
800
#223BB9
oklch(42.7% 0.199 267.5)
-
Step 900
900 (this color)
#243D9A
oklch(40.2% 0.155 267.4)
-
Step 950
950
#122155
oklch(27.1% 0.097 267.3)
#243D9A 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) | #004B9D | 0.037 |
| Deuteranopia (no green cones) | #004098 | 0.023 |
| Tritanopia (no blue cones) | #005565 | 0.123 |
| Achromatopsia (no color) | #464646 | 0.155 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243D9A
#243D9A
oklch(40.2% 0.155 267.4)
- #5B4500
#5B4500
oklch(40.3% 0.082 87.8)
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 #243D9A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.030
- Cobalt #1E488F ΔE 0.035
- Blueberry #464196 ΔE 0.049
- Dark Slate Blue #483D8B ΔE 0.055
- Twilight Blue #0A437A ΔE 0.060
- Dusk Blue #26538D ΔE 0.066
- Light Navy #155084 ΔE 0.067
- Indigo Blue #3A18B1 ΔE 0.073
Use #243D9A 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.