#243FA1
Closest named color: Sapphire (#2138AB). oklch(41.2% 0.162 267), rgb(36, 63, 161).
Aa
White text reads best on this color (9.12:1).
About this color
#243FA1 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 9.12:1.
| Hue family | Blues |
| Lightness | dark (41%) |
| Chroma | vivid (0.162) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.30:1 |
| White text | 9.12:1 |
Values
| HEX | #243FA1 |
| RGB | rgb(36, 63, 161) |
| HSL | hsl(227, 63%, 39%) |
| OKLCH | oklch(41.2% 0.162 267) |
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 #243FA1 | 9.12:1 | AAA | Lc -94.9 | Preferred for body text |
| Black text on #243FA1 | 2.30:1 | Fails | Lc 13.5 | Not readable |
| #243FA1 text on white | 9.12:1 | AAA | Lc 90.4 | Preferred for body text |
| #243FA1 text on black | 2.30:1 | Fails | Lc -11.9 | 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 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
#A5BFFF
oklch(80.9% 0.095 267.2)
-
Step 400
400
#769BFE
oklch(70.6% 0.151 267.1)
-
Step 500
500
#557EFD
oklch(63% 0.194 267.2)
-
Step 600
600
#3D64EC
oklch(55.7% 0.21 267)
-
Step 700
700
#3051CD
oklch(49% 0.195 267.2)
-
Step 800
800 (this color)
#243FA1
oklch(41.2% 0.162 267)
-
Step 900
900
#243A83
oklch(37.6% 0.126 267.4)
-
Step 950
950
#15234D
oklch(27% 0.08 267.1)
#243FA1 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) | #004EA4 | 0.039 |
| Deuteranopia (no green cones) | #00429F | 0.022 |
| Tritanopia (no blue cones) | #00586A | 0.126 |
| Achromatopsia (no color) | #484848 | 0.162 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243FA1
#243FA1
oklch(41.2% 0.162 267)
- #5F4700
#5F4700
oklch(41.2% 0.084 86.4)
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 #243FA1, closest first.
No curated palette has a color within ΔE 0.04 of #243FA1.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.023
- Cobalt #1E488F ΔE 0.039
- Blueberry #464196 ΔE 0.049
- Dark Slate Blue #483D8B ΔE 0.060
- Blue Blue #2242C7 ΔE 0.062
- Dusk Blue #26538D ΔE 0.066
- Twilight Blue #0A437A ΔE 0.070
- Light Navy #155084 ΔE 0.070
Use #243FA1 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.