#243C9A
Closest named color: Sapphire (#2138AB). oklch(40% 0.156 267.6), rgb(36, 60, 154).
Aa
White text reads best on this color (9.59:1).
About this color
#243C9A is a dark, vivid blue. In OKLCH its lightness is 40%, its chroma 0.156 and its hue 268°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.029 away. White text reads best on it, at 9.59:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | vivid (0.156) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.18:1 |
| White text | 9.59:1 |
Values
| HEX | #243C9A |
| RGB | rgb(36, 60, 154) |
| HSL | hsl(228, 62%, 37%) |
| OKLCH | oklch(40% 0.156 267.6) |
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 #243C9A | 9.59:1 | AAA | Lc -96.0 | Preferred for body text |
| Black text on #243C9A | 2.18:1 | Fails | Lc 12.3 | Not readable |
| #243C9A text on white | 9.59:1 | AAA | Lc 91.7 | Preferred for body text |
| #243C9A text on black | 2.18:1 | Fails | Lc -10.7 | 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
#A6BFFF
oklch(80.9% 0.095 267.8)
-
Step 400
400
#779BFF
oklch(70.7% 0.152 267.5)
-
Step 500
500
#567DFF
oklch(63% 0.198 267.8)
-
Step 600
600
#385BFF
oklch(55.5% 0.245 267.7)
-
Step 700
700
#2A45E6
oklch(49.1% 0.241 267.7)
-
Step 800
800
#223BBA
oklch(42.8% 0.2 267.5)
-
Step 900
900 (this color)
#243C9A
oklch(40% 0.156 267.6)
-
Step 950
950
#122056
oklch(27% 0.1 268)
#243C9A 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 | 0.040 |
| Deuteranopia (no green cones) | #004098 | 0.023 |
| Tritanopia (no blue cones) | #005465 | 0.123 |
| Achromatopsia (no color) | #454545 | 0.156 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243C9A
#243C9A
oklch(40% 0.156 267.6)
- #5A4400
#5A4400
oklch(39.9% 0.082 87.6)
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 #243C9A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.029
- Cobalt #1E488F ΔE 0.037
- Blueberry #464196 ΔE 0.050
- Dark Slate Blue #483D8B ΔE 0.056
- Twilight Blue #0A437A ΔE 0.061
- Light Navy #155084 ΔE 0.069
- Dusk Blue #26538D ΔE 0.069
- Indigo Blue #3A18B1 ΔE 0.071
Use #243C9A 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.