#553B78
Closest named color: Dark Slate Blue (#483D8B). oklch(41.1% 0.102 301.8), rgb(85, 59, 120).
Aa
White text reads best on this color (9.19:1).
About this color
#553B78 is a dark, moderately saturated purple. In OKLCH its lightness is 41%, its chroma 0.102 and its hue 302°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.039 away. White text reads best on it, at 9.19:1.
| Hue family | Purples |
| Lightness | dark (41%) |
| Chroma | moderately saturated (0.102) |
| Temperature | in between |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.28:1 |
| White text | 9.19:1 |
Values
| HEX | #553B78 |
| RGB | rgb(85, 59, 120) |
| HSL | hsl(266, 34%, 35%) |
| OKLCH | oklch(41.1% 0.102 301.8) |
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 #553B78 | 9.19:1 | AAA | Lc -95.4 | Preferred for body text |
| Black text on #553B78 | 2.28:1 | Fails | Lc 12.9 | Not readable |
| #553B78 text on white | 9.19:1 | AAA | Lc 91.0 | Preferred for body text |
| #553B78 text on black | 2.28:1 | Fails | Lc -11.3 | 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
#F6F4FA
oklch(97% 0.008 301.4)
-
Step 100
100
#ECE7F4
oklch(93.6% 0.018 303.4)
-
Step 200
200
#DDD4EC
oklch(88.4% 0.034 302.7)
-
Step 300
300
#C7B8E1
oklch(80.8% 0.059 301.8)
-
Step 400
400
#AB92D2
oklch(70.6% 0.095 301.9)
-
Step 500
500
#9776C7
oklch(63% 0.123 301.8)
-
Step 600
600
#825EB3
oklch(55.6% 0.132 301.8)
-
Step 700
700
#6E4D9A
oklch(49.1% 0.123 301.9)
-
Step 800
800 (this color)
#553B78
oklch(41.1% 0.102 301.8)
-
Step 900
900
#493664
oklch(37.6% 0.079 301.8)
-
Step 950
950
#2B203B
oklch(27% 0.051 301.9)
#553B78 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) | #28477A | 0.071 |
| Deuteranopia (no green cones) | #2F4776 | 0.065 |
| Tritanopia (no blue cones) | #4E4654 | 0.077 |
| Achromatopsia (no color) | #484848 | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #553B78
#553B78
oklch(41.1% 0.102 301.8)
- #425200
#425200
oklch(41% 0.099 121.7)
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 #553B78, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.039
- Blueberry #464196 ΔE 0.056
- Twilight #4E518B ΔE 0.062
- Rebecca Purple #663399 ΔE 0.066
- Dusk #4E5481 ΔE 0.068
- Dusty Grape #545775 ΔE 0.081
- Cobalt #1E488F ΔE 0.084
- Dusk Blue #26538D ΔE 0.087
Use #553B78 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.