#243F66
Closest named color: Dark Grey Blue (#29465B). oklch(36.6% 0.075 257.6), rgb(36, 63, 102).
Aa
White text reads best on this color (10.61:1).
About this color
#243F66 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.075 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.034 away. White text reads best on it, at 10.61:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.075) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 1.97:1 |
| White text | 10.61:1 |
Values
| HEX | #243F66 |
| RGB | rgb(36, 63, 102) |
| HSL | hsl(215, 48%, 27%) |
| OKLCH | oklch(36.6% 0.075 257.6) |
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 #243F66 | 10.61:1 | AAA | Lc -98.4 | Preferred for body text |
| Black text on #243F66 | 1.97:1 | Fails | Lc 9.5 | Not readable |
| #243F66 text on white | 10.61:1 | AAA | Lc 94.5 | Preferred for body text |
| #243F66 text on black | 1.97:1 | Fails | Lc -8.1 | 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 900.
-
Step 50
50
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E3EAF5
oklch(93.5% 0.017 259.4)
-
Step 200
200
#CCDAEE
oklch(88.4% 0.031 257.2)
-
Step 300
300
#AAC2E6
oklch(80.8% 0.057 258.4)
-
Step 400
400
#7DA2D9
oklch(70.6% 0.091 258.1)
-
Step 500
500
#5B8ACF
oklch(63% 0.117 257.9)
-
Step 600
600
#4173BC
oklch(55.6% 0.126 257.9)
-
Step 700
700
#3360A2
oklch(49.1% 0.117 258)
-
Step 800
800
#2B4F83
oklch(42.8% 0.096 257.7)
-
Step 900
900 (this color)
#243F66
oklch(36.6% 0.075 257.6)
-
Step 950
950
#17273E
oklch(27.1% 0.048 257.5)
#243F66 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) | #2E4268 | 0.017 |
| Deuteranopia (no green cones) | #263C65 | 0.009 |
| Tritanopia (no blue cones) | #00484D | 0.064 |
| Achromatopsia (no color) | #3E3E3E | 0.075 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243F66
#243F66
oklch(36.6% 0.075 257.6)
- #543902
#543902
oklch(36.6% 0.075 78.4)
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 #243F66, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.034
- Twilight Blue #0A437A ΔE 0.037
- Marine Blue #01386A ΔE 0.038
- Prussian Blue #1D3557 ΔE 0.040
- Dark Blue Grey #1F3B4D ΔE 0.045
- Charcoal #264653 ΔE 0.045
- Midnight Green #073B4C ΔE 0.055
- Marine #042E60 ΔE 0.064
Use #243F66 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.