#42497B
Closest named color: Twilight (#4E518B). oklch(42.3% 0.083 276.2), rgb(66, 73, 123).
Aa
White text reads best on this color (8.49:1).
About this color
#42497B is a dark, moderately saturated blue. In OKLCH its lightness is 42%, its chroma 0.083 and its hue 276°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight (#4E518B), ΔE 0.038 away. White text reads best on it, at 8.49:1.
| Hue family | Blues |
| Lightness | dark (42%) |
| Chroma | moderately saturated (0.083) |
| Temperature | cool |
| Nearest name | Twilight (#4E518B) |
| Black text | 2.47:1 |
| White text | 8.49:1 |
Values
| HEX | #42497B |
| RGB | rgb(66, 73, 123) |
| HSL | hsl(233, 30%, 37%) |
| OKLCH | oklch(42.3% 0.083 276.2) |
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 #42497B | 8.49:1 | AAA | Lc -93.7 | Preferred for body text |
| Black text on #42497B | 2.47:1 | Fails | Lc 14.8 | Not readable |
| #42497B text on white | 8.49:1 | AAA | Lc 89.2 | Fine for body text |
| #42497B text on black | 2.47:1 | Fails | Lc -13.1 | Not readable |
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
#F4F5FA
oklch(97.1% 0.007 277.2)
-
Step 100
100
#E7E9F4
oklch(93.6% 0.015 277.8)
-
Step 200
200
#D4D8EB
oklch(88.5% 0.026 276.4)
-
Step 300
300
#B8BFE1
oklch(81% 0.049 276.1)
-
Step 400
400
#939DD1
oklch(70.7% 0.077 275.8)
-
Step 500
500
#7984C5
oklch(63.1% 0.099 275.9)
-
Step 600
600
#636DB2
oklch(55.7% 0.107 276.1)
-
Step 700
700
#525A99
oklch(49% 0.101 276.5)
-
Step 800
800 (this color)
#42497B
oklch(42.3% 0.083 276.2)
-
Step 900
900
#383E64
oklch(37.7% 0.065 276)
-
Step 950
950
#21253A
oklch(27.1% 0.04 275.2)
#42497B 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) | #374F7D | 0.021 |
| Deuteranopia (no green cones) | #324B7A | 0.022 |
| Tritanopia (no blue cones) | #2F535C | 0.073 |
| Achromatopsia (no color) | #4D4D4D | 0.083 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42497B
#42497B
oklch(42.3% 0.083 276.2)
- #5B4D08
#5B4D08
oklch(42.2% 0.083 96.3)
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 #42497B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight #4E518B ΔE 0.038
- Dusk #4E5481 ΔE 0.039
- Dusk Blue #26538D ΔE 0.045
- Dark Slate Blue #483D8B ΔE 0.046
- Light Navy #155084 ΔE 0.048
- Light Navy Blue #2E5A88 ΔE 0.052
- Cobalt #1E488F ΔE 0.053
- Blueberry #464196 ΔE 0.053
Use #42497B 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.