#42517C
Closest named color: Dusk (#4E5481). oklch(44.2% 0.074 268.6), rgb(66, 81, 124).
Aa
White text reads best on this color (7.77:1).
About this color
#42517C is a dark, moderately saturated blue. In OKLCH its lightness is 44%, its chroma 0.074 and its hue 269°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk (#4E5481), ΔE 0.022 away. White text reads best on it, at 7.77:1.
| Hue family | Blues |
| Lightness | dark (44%) |
| Chroma | moderately saturated (0.074) |
| Temperature | cool |
| Nearest name | Dusk (#4E5481) |
| Black text | 2.69:1 |
| White text | 7.77:1 |
Values
| HEX | #42517C |
| RGB | rgb(66, 81, 124) |
| HSL | hsl(224, 31%, 37%) |
| OKLCH | oklch(44.2% 0.074 268.6) |
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 #42517C | 7.77:1 | AAA | Lc -91.7 | Preferred for body text |
| Black text on #42517C | 2.69:1 | Fails | Lc 17.1 | Dividers and decoration only |
| #42517C text on white | 7.77:1 | AAA | Lc 86.9 | Fine for body text |
| #42517C text on black | 2.69:1 | Fails | Lc -15.2 | 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
#F4F5F9
oklch(97.1% 0.005 275)
-
Step 100
100
#E6EAF2
oklch(93.6% 0.012 264.5)
-
Step 200
200
#D2D9EA
oklch(88.5% 0.025 267.9)
-
Step 300
300
#B5C0DD
oklch(80.9% 0.043 269)
-
Step 400
400
#8F9FCC
oklch(70.6% 0.069 269.4)
-
Step 500
500
#7387BF
oklch(63% 0.088 268.7)
-
Step 600
600
#5C70AC
oklch(55.5% 0.097 269.1)
-
Step 700
700
#4C5E93
oklch(49.1% 0.088 268.8)
-
Step 800
800 (this color)
#42517C
oklch(44.2% 0.074 268.6)
-
Step 900
900
#354060
oklch(37.7% 0.057 269.1)
-
Step 950
950
#1F2638
oklch(27.1% 0.035 267.7)
#42517C 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) | #41557E | 0.012 |
| Deuteranopia (no green cones) | #3C507B | 0.009 |
| Tritanopia (no blue cones) | #2D5A61 | 0.065 |
| Achromatopsia (no color) | #525252 | 0.074 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42517C
#42517C
oklch(44.2% 0.074 268.6)
- #64511D
#64511D
oklch(44.3% 0.074 88.8)
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 #42517C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk #4E5481 ΔE 0.022
- YInMn Blue #415A77 ΔE 0.031
- Twilight #4E518B ΔE 0.031
- Light Navy Blue #2E5A88 ΔE 0.034
- Dusty Grape #545775 ΔE 0.037
- Dusk Blue #26538D ΔE 0.040
- Denim Blue #3B5B92 ΔE 0.041
- Light Navy #155084 ΔE 0.046
Use #42517C 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.