#42538E
Closest named color: Twilight (#4E518B). oklch(45.7% 0.099 270), rgb(66, 83, 142).
Aa
White text reads best on this color (7.34:1).
About this color
#42538E is a medium-dark, moderately saturated blue. In OKLCH its lightness is 46%, its chroma 0.099 and its hue 270°. 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 7.34:1.
| Hue family | Blues |
| Lightness | medium-dark (46%) |
| Chroma | moderately saturated (0.099) |
| Temperature | cool |
| Nearest name | Twilight (#4E518B) |
| Black text | 2.85:1 |
| White text | 7.34:1 |
Values
| HEX | #42538E |
| RGB | rgb(66, 83, 142) |
| HSL | hsl(227, 37%, 41%) |
| OKLCH | oklch(45.7% 0.099 270) |
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 #42538E | 7.34:1 | AAA | Lc -90.2 | Preferred for body text |
| Black text on #42538E | 2.85:1 | Fails | Lc 18.6 | Dividers and decoration only |
| #42538E text on white | 7.34:1 | AAA | Lc 85.4 | Fine for body text |
| #42538E text on black | 2.85:1 | Fails | Lc -16.6 | 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
#E5EAF5
oklch(93.6% 0.016 266.3)
-
Step 200
200
#D1D9EF
oklch(88.6% 0.031 269.8)
-
Step 300
300
#B2C0E7
oklch(81% 0.057 269.6)
-
Step 400
400
#8A9EDB
oklch(70.7% 0.093 270)
-
Step 500
500
#6E85D1
oklch(63.2% 0.118 270)
-
Step 600
600
#566DBE
oklch(55.5% 0.129 269.9)
-
Step 700
700
#475BA4
oklch(49.2% 0.119 270)
-
Step 800
800 (this color)
#42538E
oklch(45.7% 0.099 270)
-
Step 900
900
#323F6A
oklch(37.8% 0.076 269.8)
-
Step 950
950
#1D253E
oklch(27% 0.048 269.5)
#42538E 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) | #3B5A90 | 0.020 |
| Deuteranopia (no green cones) | #33538D | 0.018 |
| Tritanopia (no blue cones) | #1F6069 | 0.089 |
| Achromatopsia (no color) | #565656 | 0.099 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42538E
#42538E
oklch(45.7% 0.099 270)
- #6B5400
#6B5400
oklch(45.7% 0.093 90.3)
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 #42538E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight #4E518B ΔE 0.017
- Denim Blue #3B5B92 ΔE 0.023
- Dusk #4E5481 ΔE 0.028
- Dusk Blue #26538D ΔE 0.031
- Light Navy Blue #2E5A88 ΔE 0.032
- Dusky Blue #475F94 ΔE 0.036
- Denim #3B638C ΔE 0.048
- YInMn Blue #415A77 ΔE 0.048
Use #42538E 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.