#243FA3
Closest named color: Sapphire (#2138AB). oklch(41.4% 0.165 267.1), rgb(36, 63, 163).
Aa
White text reads best on this color (9.07:1).
About this color
#243FA3 is a dark, vivid blue. In OKLCH its lightness is 41%, its chroma 0.165 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.021 away. White text reads best on it, at 9.07:1.
| Hue family | Blues |
| Lightness | dark (41%) |
| Chroma | vivid (0.165) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.31:1 |
| White text | 9.07:1 |
Values
| HEX | #243FA3 |
| RGB | rgb(36, 63, 163) |
| HSL | hsl(227, 64%, 39%) |
| OKLCH | oklch(41.4% 0.165 267.1) |
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 #243FA3 | 9.07:1 | AAA | Lc -94.7 | Preferred for body text |
| Black text on #243FA3 | 2.31:1 | Fails | Lc 13.7 | Not readable |
| #243FA3 text on white | 9.07:1 | AAA | Lc 90.3 | Preferred for body text |
| #243FA3 text on black | 2.31:1 | Fails | Lc -12.0 | 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
#F1F5FE
oklch(97% 0.013 266.7)
-
Step 100
100
#E1EAFD
oklch(93.6% 0.028 265.4)
-
Step 200
200
#C9D9FE
oklch(88.5% 0.054 266.8)
-
Step 300
300
#A5BFFF
oklch(80.9% 0.095 267.2)
-
Step 400
400
#769BFF
oklch(70.7% 0.152 267.2)
-
Step 500
500
#547EFF
oklch(63.1% 0.197 267)
-
Step 600
600
#3C63EE
oklch(55.6% 0.214 267)
-
Step 700
700
#2F51CF
oklch(49.2% 0.198 267)
-
Step 800
800 (this color)
#243FA3
oklch(41.4% 0.165 267.1)
-
Step 900
900
#233A85
oklch(37.7% 0.129 267.1)
-
Step 950
950
#15234E
oklch(27.1% 0.081 267.2)
#243FA3 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) | #004FA6 | 0.041 |
| Deuteranopia (no green cones) | #0043A1 | 0.022 |
| Tritanopia (no blue cones) | #00596B | 0.129 |
| Achromatopsia (no color) | #494949 | 0.165 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243FA3
#243FA3
oklch(41.4% 0.165 267.1)
- #5F4800
#5F4800
oklch(41.5% 0.085 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 #243FA3, closest first.
No curated palette has a color within ΔE 0.04 of #243FA3.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.021
- Cobalt #1E488F ΔE 0.041
- Blueberry #464196 ΔE 0.050
- Blue Blue #2242C7 ΔE 0.058
- Dark Slate Blue #483D8B ΔE 0.062
- Dusk Blue #26538D ΔE 0.068
- Majorelle Blue #3F37C9 ΔE 0.070
- Indigo Blue #3A18B1 ΔE 0.070
Use #243FA3 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.