#42578E
Closest named color: Denim Blue (#3B5B92). oklch(46.6% 0.093 267), rgb(66, 87, 142).
Aa
White text reads best on this color (7.03:1).
About this color
#42578E is a medium-dark, moderately saturated blue. In OKLCH its lightness is 47%, its chroma 0.093 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Denim Blue (#3B5B92), ΔE 0.013 away. White text reads best on it, at 7.03:1.
| Hue family | Blues |
| Lightness | medium-dark (47%) |
| Chroma | moderately saturated (0.093) |
| Temperature | cool |
| Nearest name | Denim Blue (#3B5B92) |
| Black text | 2.98:1 |
| White text | 7.03:1 |
Values
| HEX | #42578E |
| RGB | rgb(66, 87, 142) |
| HSL | hsl(223, 37%, 41%) |
| OKLCH | oklch(46.6% 0.093 267) |
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 #42578E | 7.03:1 | AAA | Lc -89.2 | Fine for body text |
| Black text on #42578E | 2.98:1 | Fails | Lc 19.8 | Dividers and decoration only |
| #42578E text on white | 7.03:1 | AAA | Lc 84.3 | Fine for body text |
| #42578E text on black | 2.98:1 | Fails | Lc -17.7 | 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 700.
-
Step 50
50
#F3F5FA
oklch(97% 0.007 268.5)
-
Step 100
100
#E6EAF3
oklch(93.7% 0.013 266.7)
-
Step 200
200
#D2D9EA
oklch(88.5% 0.025 267.9)
-
Step 300
300
#B3C0DF
oklch(80.8% 0.046 267.4)
-
Step 400
400
#8CA0CF
oklch(70.8% 0.073 266.6)
-
Step 500
500
#7088C2
oklch(63.2% 0.092 266.6)
-
Step 600
600
#5971AE
oklch(55.7% 0.099 266.9)
-
Step 700
700 (this color)
#42578E
oklch(46.6% 0.093 267)
-
Step 800
800
#3C4D79
oklch(42.7% 0.077 267.1)
-
Step 900
900
#334062
oklch(37.6% 0.061 267.5)
-
Step 950
950
#1E2639
oklch(27% 0.037 266.4)
#42578E 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) | #415C90 | 0.014 |
| Deuteranopia (no green cones) | #39568D | 0.012 |
| Tritanopia (no blue cones) | #1E636B | 0.085 |
| Achromatopsia (no color) | #595959 | 0.093 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42578E
#42578E
oklch(46.6% 0.093 267)
- #705505
#705505
oklch(46.5% 0.093 86.7)
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 #42578E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Denim Blue #3B5B92 ΔE 0.013
- Twilight #4E518B ΔE 0.022
- Dusky Blue #475F94 ΔE 0.025
- Dusk #4E5481 ΔE 0.025
- Light Navy Blue #2E5A88 ΔE 0.026
- Dusk Blue #26538D ΔE 0.035
- Denim #3B638C ΔE 0.036
- YInMn Blue #415A77 ΔE 0.042
Use #42578E 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.