#243D9F
Closest named color: Sapphire (#2138AB). oklch(40.6% 0.162 267.5), rgb(36, 61, 159).
Aa
White text reads best on this color (9.36:1).
About this color
#243D9F is a dark, vivid blue. In OKLCH its lightness is 41%, its chroma 0.162 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.023 away. White text reads best on it, at 9.36:1.
| Hue family | Blues |
| Lightness | dark (41%) |
| Chroma | vivid (0.162) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.24:1 |
| White text | 9.36:1 |
Values
| HEX | #243D9F |
| RGB | rgb(36, 61, 159) |
| HSL | hsl(228, 63%, 38%) |
| OKLCH | oklch(40.6% 0.162 267.5) |
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 #243D9F | 9.36:1 | AAA | Lc -95.4 | Preferred for body text |
| Black text on #243D9F | 2.24:1 | Fails | Lc 12.9 | Not readable |
| #243D9F text on white | 9.36:1 | AAA | Lc 91.0 | Preferred for body text |
| #243D9F text on black | 2.24:1 | Fails | Lc -11.3 | 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 800.
-
Step 50
50
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E2EAFD
oklch(93.7% 0.027 267.5)
-
Step 200
200
#CAD9FD
oklch(88.6% 0.052 267.4)
-
Step 300
300
#A6BFFE
oklch(80.9% 0.094 267.6)
-
Step 400
400
#779BFE
oklch(70.7% 0.151 267.4)
-
Step 500
500
#567EFD
oklch(63.1% 0.194 267.4)
-
Step 600
600
#3E63EC
oklch(55.6% 0.211 267.4)
-
Step 700
700
#3151CD
oklch(49.1% 0.195 267.4)
-
Step 800
800 (this color)
#243D9F
oklch(40.6% 0.162 267.5)
-
Step 900
900
#243A83
oklch(37.6% 0.126 267.4)
-
Step 950
950
#15234D
oklch(27% 0.08 267.1)
#243D9F 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) | #004CA2 | 0.039 |
| Deuteranopia (no green cones) | #00419D | 0.022 |
| Tritanopia (no blue cones) | #005668 | 0.126 |
| Achromatopsia (no color) | #474747 | 0.162 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243D9F
#243D9F
oklch(40.6% 0.162 267.5)
- #5C4600
#5C4600
oklch(40.6% 0.083 88.1)
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 #243D9F, closest first.
No curated palette has a color within ΔE 0.04 of #243D9F.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.023
- Cobalt #1E488F ΔE 0.040
- Blueberry #464196 ΔE 0.050
- Dark Slate Blue #483D8B ΔE 0.059
- Blue Blue #2242C7 ΔE 0.066
- Twilight Blue #0A437A ΔE 0.068
- Indigo Blue #3A18B1 ΔE 0.069
- Dusk Blue #26538D ΔE 0.069
Use #243D9F 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.