#42518C
Closest named color: Twilight (#4E518B). oklch(45.1% 0.098 271.2), rgb(66, 81, 140).
Aa
White text reads best on this color (7.53:1).
About this color
#42518C is a medium-dark, moderately saturated blue. In OKLCH its lightness is 45%, its chroma 0.098 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight (#4E518B), ΔE 0.017 away. White text reads best on it, at 7.53:1.
| Hue family | Blues |
| Lightness | medium-dark (45%) |
| Chroma | moderately saturated (0.098) |
| Temperature | cool |
| Nearest name | Twilight (#4E518B) |
| Black text | 2.78:1 |
| White text | 7.53:1 |
Values
| HEX | #42518C |
| RGB | rgb(66, 81, 140) |
| HSL | hsl(228, 36%, 40%) |
| OKLCH | oklch(45.1% 0.098 271.2) |
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 #42518C | 7.53:1 | AAA | Lc -90.9 | Preferred for body text |
| Black text on #42518C | 2.78:1 | Fails | Lc 18.0 | Dividers and decoration only |
| #42518C text on white | 7.53:1 | AAA | Lc 86.1 | Fine for body text |
| #42518C text on black | 2.78:1 | Fails | Lc -16.0 | Dividers and decoration only |
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
#F3F5FB
oklch(97% 0.008 271.3)
-
Step 100
100
#E6EAF5
oklch(93.7% 0.015 270)
-
Step 200
200
#D1D8EF
oklch(88.4% 0.033 272.2)
-
Step 300
300
#B3BFE7
oklch(80.9% 0.058 272)
-
Step 400
400
#8B9EDA
oklch(70.7% 0.091 270.5)
-
Step 500
500
#7084D0
oklch(63% 0.117 271.5)
-
Step 600
600
#596DBE
oklch(55.7% 0.128 271.3)
-
Step 700
700
#495AA3
oklch(49% 0.118 271.6)
-
Step 800
800 (this color)
#42518C
oklch(45.1% 0.098 271.2)
-
Step 900
900
#333E6A
oklch(37.6% 0.077 271.7)
-
Step 950
950
#1E253E
oklch(27.1% 0.048 271.1)
#42518C 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) | #39588E | 0.021 |
| Deuteranopia (no green cones) | #31518B | 0.021 |
| Tritanopia (no blue cones) | #215E67 | 0.089 |
| Achromatopsia (no color) | #545454 | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42518C
#42518C
oklch(45.1% 0.098 271.2)
- #695300
#695300
oklch(45.2% 0.092 91)
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 #42518C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight #4E518B ΔE 0.017
- Dusk #4E5481 ΔE 0.028
- Denim Blue #3B5B92 ΔE 0.028
- Dusk Blue #26538D ΔE 0.031
- Light Navy Blue #2E5A88 ΔE 0.034
- Dusky Blue #475F94 ΔE 0.042
- Light Navy #155084 ΔE 0.048
- Blueberry #464196 ΔE 0.048
Use #42518C 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.