#42528B
Closest named color: Twilight (#4E518B). oklch(45.3% 0.095 270.4), rgb(66, 82, 139).
Aa
White text reads best on this color (7.46:1).
About this color
#42528B is a medium-dark, moderately saturated blue. In OKLCH its lightness is 45%, its chroma 0.095 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 7.46:1.
| Hue family | Blues |
| Lightness | medium-dark (45%) |
| Chroma | moderately saturated (0.095) |
| Temperature | cool |
| Nearest name | Twilight (#4E518B) |
| Black text | 2.81:1 |
| White text | 7.46:1 |
Values
| HEX | #42528B |
| RGB | rgb(66, 82, 139) |
| HSL | hsl(227, 36%, 40%) |
| OKLCH | oklch(45.3% 0.095 270.4) |
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 #42528B | 7.46:1 | AAA | Lc -90.7 | Preferred for body text |
| Black text on #42528B | 2.81:1 | Fails | Lc 18.2 | Dividers and decoration only |
| #42528B text on white | 7.46:1 | AAA | Lc 85.8 | Fine for body text |
| #42528B text on black | 2.81:1 | Fails | Lc -16.2 | 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
#D1D9EE
oklch(88.6% 0.03 269.1)
-
Step 300
300
#B3C0E6
oklch(81% 0.056 270.3)
-
Step 400
400
#8B9ED9
oklch(70.7% 0.089 270.3)
-
Step 500
500
#6F85CF
oklch(63.1% 0.115 270.3)
-
Step 600
600
#586DBB
oklch(55.5% 0.124 270.6)
-
Step 700
700
#485BA2
oklch(49.1% 0.116 270.4)
-
Step 800
800 (this color)
#42528B
oklch(45.3% 0.095 270.4)
-
Step 900
900
#333F69
oklch(37.8% 0.074 270.5)
-
Step 950
950
#1E253E
oklch(27.1% 0.048 271.1)
#42528B 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) | #3B588D | 0.018 |
| Deuteranopia (no green cones) | #34528A | 0.018 |
| Tritanopia (no blue cones) | #225E68 | 0.084 |
| Achromatopsia (no color) | #555555 | 0.095 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42528B
#42528B
oklch(45.3% 0.095 270.4)
- #6A5300
#6A5300
oklch(45.3% 0.093 90.1)
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 #42528B, 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 0.025
- Denim Blue #3B5B92 ΔE 0.026
- Dusk Blue #26538D ΔE 0.031
- Light Navy Blue #2E5A88 ΔE 0.032
- Dusky Blue #475F94 ΔE 0.039
- YInMn Blue #415A77 ΔE 0.046
- Light Navy #155084 ΔE 0.048
Use #42528B 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.