#42558B
Closest named color: Twilight (#4E518B). oklch(46% 0.091 268), rgb(66, 85, 139).
Aa
White text reads best on this color (7.23:1).
About this color
#42558B is a medium-dark, moderately saturated blue. In OKLCH its lightness is 46%, its chroma 0.091 and its hue 268°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight (#4E518B), ΔE 0.019 away. White text reads best on it, at 7.23:1.
| Hue family | Blues |
| Lightness | medium-dark (46%) |
| Chroma | moderately saturated (0.091) |
| Temperature | cool |
| Nearest name | Twilight (#4E518B) |
| Black text | 2.90:1 |
| White text | 7.23:1 |
Values
| HEX | #42558B |
| RGB | rgb(66, 85, 139) |
| HSL | hsl(224, 36%, 40%) |
| OKLCH | oklch(46% 0.091 268) |
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 #42558B | 7.23:1 | AAA | Lc -89.9 | Fine for body text |
| Black text on #42558B | 2.90:1 | Fails | Lc 19.0 | Dividers and decoration only |
| #42558B text on white | 7.23:1 | AAA | Lc 85.0 | Fine for body text |
| #42558B text on black | 2.90:1 | Fails | Lc -17.0 | 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 700.
-
Step 50
50
#F4F5FA
oklch(97.1% 0.007 277.2)
-
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
#B4C0DE
oklch(80.8% 0.044 268.1)
-
Step 400
400
#8EA0CE
oklch(70.9% 0.071 268)
-
Step 500
500
#7287C1
oklch(63% 0.091 268.5)
-
Step 600
600
#5B70AD
oklch(55.5% 0.098 268.6)
-
Step 700
700 (this color)
#42558B
oklch(46% 0.091 268)
-
Step 800
800
#3D4D79
oklch(42.7% 0.076 267.9)
-
Step 900
900
#344061
oklch(37.6% 0.059 268.2)
-
Step 950
950
#1F2639
oklch(27.1% 0.037 268.4)
#42558B 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) | #405A8D | 0.014 |
| Deuteranopia (no green cones) | #38548A | 0.013 |
| Tritanopia (no blue cones) | #216169 | 0.083 |
| Achromatopsia (no color) | #575757 | 0.091 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42558B
#42558B
oklch(46% 0.091 268)
- #6D5406
#6D5406
oklch(45.9% 0.091 88)
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 #42558B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight #4E518B ΔE 0.019
- Denim Blue #3B5B92 ΔE 0.019
- Dusk #4E5481 ΔE 0.022
- Light Navy Blue #2E5A88 ΔE 0.026
- Dusky Blue #475F94 ΔE 0.032
- Dusk Blue #26538D ΔE 0.032
- YInMn Blue #415A77 ΔE 0.040
- Denim #3B638C ΔE 0.041
Use #42558B 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.