#243BB9
Closest named color: Sapphire (#2138AB). oklch(42.7% 0.198 268), rgb(36, 59, 185).
Aa
White text reads best on this color (8.74:1).
About this color
#243BB9 is a dark, vivid blue. In OKLCH its lightness is 43%, its chroma 0.198 and its hue 268°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.025 away. White text reads best on it, at 8.74:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | vivid (0.198) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.40:1 |
| White text | 8.74:1 |
Values
| HEX | #243BB9 |
| RGB | rgb(36, 59, 185) |
| HSL | hsl(231, 67%, 43%) |
| OKLCH | oklch(42.7% 0.198 268) |
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 #243BB9 | 8.74:1 | AAA | Lc -93.7 | Preferred for body text |
| Black text on #243BB9 | 2.40:1 | Fails | Lc 14.9 | Not readable |
| #243BB9 text on white | 8.74:1 | AAA | Lc 89.1 | Fine for body text |
| #243BB9 text on black | 2.40:1 | Fails | Lc -13.1 | 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
#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
#789BFF
oklch(70.8% 0.152 267.9)
-
Step 500
500
#577DFF
oklch(63.1% 0.197 268)
-
Step 600
600
#3A5BFF
oklch(55.6% 0.244 268.1)
-
Step 700
700
#2C45E5
oklch(49% 0.24 268)
-
Step 800
800 (this color)
#243BB9
oklch(42.7% 0.198 268)
-
Step 900
900
#203592
oklch(37.7% 0.155 268)
-
Step 950
950
#122055
oklch(26.9% 0.098 267.9)
#243BB9 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) | #0052BD | 0.052 |
| Deuteranopia (no green cones) | #0044B7 | 0.024 |
| Tritanopia (no blue cones) | #005E75 | 0.154 |
| Achromatopsia (no color) | #4B4B4B | 0.199 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243BB9
#243BB9
oklch(42.7% 0.198 268)
- #634B00
#634B00
oklch(42.6% 0.087 87.5)
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 #243BB9, closest first.
No curated palette has a color within ΔE 0.04 of #243BB9.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.025
- Blue Blue #2242C7 ΔE 0.027
- Majorelle Blue #3F37C9 ΔE 0.041
- Indigo Blue #3A18B1 ΔE 0.061
- Blue With A Hint Of Purple #533CC6 ΔE 0.068
- Blurple #5539CC ΔE 0.074
- True Blue #010FCC ΔE 0.074
- Blueberry #464196 ΔE 0.074
Use #243BB9 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.