#555FB0
Closest named color: French Blue (#436BAD). oklch(51.7% 0.127 275.7), rgb(85, 95, 176).
Aa
White text reads best on this color (5.75:1).
About this color
#555FB0 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 52%, its chroma 0.127 and its hue 276°. Its hue sits on the cool side of the wheel. The nearest named color is French Blue (#436BAD), ΔE 0.038 away. White text reads best on it, at 5.75:1.
| Hue family | Blues |
| Lightness | medium-dark (52%) |
| Chroma | moderately saturated (0.127) |
| Temperature | cool |
| Nearest name | French Blue (#436BAD) |
| Black text | 3.65:1 |
| White text | 5.75:1 |
Values
| HEX | #555FB0 |
| RGB | rgb(85, 95, 176) |
| HSL | hsl(233, 37%, 51%) |
| OKLCH | oklch(51.7% 0.127 275.7) |
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 #555FB0 | 5.75:1 | AA | Lc -83.9 | Fine for body text |
| Black text on #555FB0 | 3.65:1 | AA large text | Lc 25.5 | Dividers and decoration only |
| #555FB0 text on white | 5.75:1 | AA | Lc 78.6 | Fine for body text |
| #555FB0 text on black | 3.65:1 | AA large text | Lc -23.2 | 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 700.
-
Step 50
50
#F4F5FB
oklch(97.1% 0.008 278.6)
-
Step 100
100
#E6E9F6
oklch(93.6% 0.018 275.6)
-
Step 200
200
#D2D8F0
oklch(88.5% 0.034 274.5)
-
Step 300
300
#B5BEE9
oklch(80.9% 0.062 275.7)
-
Step 400
400
#8F9BDE
oklch(70.6% 0.099 275.8)
-
Step 500
500
#7581D5
oklch(63% 0.127 276)
-
Step 600
600
#5E69C2
oklch(55.5% 0.137 275.7)
-
Step 700
700 (this color)
#555FB0
oklch(51.7% 0.127 275.7)
-
Step 800
800
#404888
oklch(42.8% 0.105 275.6)
-
Step 900
900
#363D6D
oklch(37.8% 0.082 275.5)
-
Step 950
950
#1F2440
oklch(27% 0.052 274.7)
#555FB0 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) | #3C6AB3 | 0.038 |
| Deuteranopia (no green cones) | #3362AE | 0.039 |
| Tritanopia (no blue cones) | #2E707F | 0.111 |
| Achromatopsia (no color) | #666666 | 0.127 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #555FB0
#555FB0
oklch(51.7% 0.127 275.7)
- #7B6700
#7B6700
oklch(51.8% 0.106 95.6)
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 #555FB0, closest first.
No curated palette has a color within ΔE 0.04 of #555FB0.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- French Blue #436BAD ΔE 0.038
- Iris #6258C4 ΔE 0.042
- Dusky Blue #475F94 ΔE 0.050
- Mid Blue #276AB3 ΔE 0.051
- Slate Blue #6A5ACD ΔE 0.057
- Dark Periwinkle #665FD1 ΔE 0.058
- Denim Blue #3B5B92 ΔE 0.061
- Light Indigo #6D5ACF ΔE 0.062
Use #555FB0 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.