#42639B
Closest named color: Dusky Blue (#475F94). oklch(50.1% 0.098 260.5), rgb(66, 99, 155).
Aa
White text reads best on this color (6.01:1).
About this color
#42639B is a medium-dark, moderately saturated blue. In OKLCH its lightness is 50%, its chroma 0.098 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Dusky Blue (#475F94), ΔE 0.014 away. White text reads best on it, at 6.01:1.
| Hue family | Blues |
| Lightness | medium-dark (50%) |
| Chroma | moderately saturated (0.098) |
| Temperature | cool |
| Nearest name | Dusky Blue (#475F94) |
| Black text | 3.48:1 |
| White text | 6.01:1 |
Values
| HEX | #42639B |
| RGB | rgb(66, 99, 155) |
| HSL | hsl(218, 40%, 43%) |
| OKLCH | oklch(50.1% 0.098 260.5) |
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 #42639B | 6.01:1 | AA | Lc -85.1 | Fine for body text |
| Black text on #42639B | 3.48:1 | AA large text | Lc 24.1 | Dividers and decoration only |
| #42639B text on white | 6.01:1 | AA | Lc 79.9 | Fine for body text |
| #42639B text on black | 3.48:1 | AA large text | Lc -21.9 | 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
#F3F6FA
oklch(97.2% 0.006 255.5)
-
Step 100
100
#E5EAF3
oklch(93.6% 0.013 262.4)
-
Step 200
200
#CFDAEB
oklch(88.5% 0.026 259)
-
Step 300
300
#AFC2E0
oklch(80.9% 0.047 259.5)
-
Step 400
400
#85A2D0
oklch(70.7% 0.075 259.5)
-
Step 500
500
#678AC4
oklch(63.1% 0.097 260.2)
-
Step 600
600
#4E73B1
oklch(55.6% 0.106 260.3)
-
Step 700
700 (this color)
#42639B
oklch(50.1% 0.098 260.5)
-
Step 800
800
#344F7B
oklch(42.7% 0.081 259.8)
-
Step 900
900
#2E4263
oklch(37.8% 0.062 260.1)
-
Step 950
950
#1B273A
oklch(27.1% 0.039 259.4)
#42639B 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) | #4C679D | 0.018 |
| Deuteranopia (no green cones) | #415F9A | 0.012 |
| Tritanopia (no blue cones) | #016F77 | 0.088 |
| Achromatopsia (no color) | #636363 | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42639B
#42639B
oklch(50.1% 0.098 260.5)
- #805C10
#805C10
oklch(50% 0.098 80.1)
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 #42639B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusky Blue #475F94 ΔE 0.014
- Denim #3B638C ΔE 0.026
- Denim Blue #3B5B92 ΔE 0.028
- French Blue #436BAD ΔE 0.033
- Muted Blue #3B719F ΔE 0.039
- Mid Blue #276AB3 ΔE 0.043
- Peacock Blue #016795 ΔE 0.043
- Light Navy Blue #2E5A88 ΔE 0.046
Use #42639B 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.