#243F97
Closest named color: Cobalt (#1E488F). oklch(40.3% 0.148 266.6), rgb(36, 63, 151).
Aa
White text reads best on this color (9.40:1).
About this color
#243F97 is a dark, vivid blue. In OKLCH its lightness is 40%, its chroma 0.148 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.028 away. White text reads best on it, at 9.40:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | vivid (0.148) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.23:1 |
| White text | 9.40:1 |
Values
| HEX | #243F97 |
| RGB | rgb(36, 63, 151) |
| HSL | hsl(226, 61%, 37%) |
| OKLCH | oklch(40.3% 0.148 266.6) |
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 #243F97 | 9.40:1 | AAA | Lc -95.6 | Preferred for body text |
| Black text on #243F97 | 2.23:1 | Fails | Lc 12.7 | Not readable |
| #243F97 text on white | 9.40:1 | AAA | Lc 91.2 | Preferred for body text |
| #243F97 text on black | 2.23:1 | Fails | Lc -11.1 | 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
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E2EAFB
oklch(93.6% 0.025 265.6)
-
Step 200
200
#CBD9FA
oklch(88.5% 0.048 267.2)
-
Step 300
300
#A7C0F9
oklch(80.9% 0.086 266.1)
-
Step 400
400
#799DF7
oklch(70.8% 0.138 266.4)
-
Step 500
500
#5881F3
oklch(63.1% 0.177 266.5)
-
Step 600
600
#4067E2
oklch(55.6% 0.192 266.7)
-
Step 700
700
#3255C4
oklch(49.1% 0.178 266.5)
-
Step 800
800 (this color)
#243F97
oklch(40.3% 0.148 266.6)
-
Step 900
900
#253C7E
oklch(37.7% 0.115 266.4)
-
Step 950
950
#16244A
oklch(27.1% 0.073 266.4)
#243F97 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) | #004C9A | 0.036 |
| Deuteranopia (no green cones) | #004195 | 0.022 |
| Tritanopia (no blue cones) | #005564 | 0.118 |
| Achromatopsia (no color) | #464646 | 0.148 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243F97
#243F97
oklch(40.3% 0.148 266.6)
- #5C4500
#5C4500
oklch(40.4% 0.083 86.9)
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 #243F97, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.028
- Sapphire #2138AB ΔE 0.037
- Blueberry #464196 ΔE 0.047
- Dark Slate Blue #483D8B ΔE 0.052
- Twilight Blue #0A437A ΔE 0.055
- Light Navy #155084 ΔE 0.060
- Dusk Blue #26538D ΔE 0.060
- Deep Sea Blue #015482 ΔE 0.073
Use #243F97 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.