#646FAB
Closest named color: French Blue (#436BAD). oklch(55.8% 0.094 275), rgb(100, 111, 171).
Aa
White text reads best on this color (4.76:1).
About this color
#646FAB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.094 and its hue 275°. Its hue sits on the cool side of the wheel. The nearest named color is French Blue (#436BAD), ΔE 0.044 away. White text reads best on it, at 4.76:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.094) |
| Temperature | cool |
| Nearest name | French Blue (#436BAD) |
| Black text | 4.40:1 |
| White text | 4.76:1 |
Values
| HEX | #646FAB |
| RGB | rgb(100, 111, 171) |
| HSL | hsl(231, 30%, 53%) |
| OKLCH | oklch(55.8% 0.094 275) |
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 #646FAB | 4.76:1 | AA | Lc -78.5 | Fine for body text |
| Black text on #646FAB | 4.40:1 | AA large text | Lc 31.0 | Non-text elements, placeholder text |
| #646FAB text on white | 4.76:1 | AA | Lc 73.0 | Content text, not long reading |
| #646FAB text on black | 4.40:1 | AA large text | Lc -28.7 | 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 600.
-
Step 50
50
#F4F5F9
oklch(97.1% 0.005 275)
-
Step 100
100
#E7E9F2
oklch(93.5% 0.012 276.1)
-
Step 200
200
#D4D8E9
oklch(88.4% 0.024 275.3)
-
Step 300
300
#B8BFDD
oklch(80.9% 0.043 275)
-
Step 400
400
#949ECB
oklch(70.7% 0.067 274.8)
-
Step 500
500
#7A85BE
oklch(63% 0.087 275.2)
-
Step 600
600 (this color)
#646FAB
oklch(55.8% 0.094 275)
-
Step 700
700
#525C92
oklch(49.1% 0.087 274.8)
-
Step 800
800
#434B77
oklch(42.6% 0.074 275)
-
Step 900
900
#393F60
oklch(37.7% 0.057 275.4)
-
Step 950
950
#212538
oklch(27% 0.036 274.6)
#646FAB 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) | #5A76AD | 0.022 |
| Deuteranopia (no green cones) | #5570AA | 0.020 |
| Tritanopia (no blue cones) | #4D7B85 | 0.084 |
| Achromatopsia (no color) | #737373 | 0.094 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #646FAB
#646FAB
oklch(55.8% 0.094 275)
- #85732B
#85732B
oklch(55.8% 0.094 95.1)
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 #646FAB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- French Blue #436BAD ΔE 0.044
- Dull Blue #49759C ΔE 0.046
- Flat Blue #3C73A8 ΔE 0.047
- Stormy Blue #507B9C ΔE 0.052
- Muted Blue #3B719F ΔE 0.053
- Windows Blue #3778BF ΔE 0.055
- Dark Lavender #856798 ΔE 0.057
- Cerulean #457B9D ΔE 0.057
Use #646FAB 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.