#646B81
Closest named color: Metallic Blue (#4F738E). oklch(53% 0.036 271.3), rgb(100, 107, 129).
Aa
White text reads best on this color (5.30:1).
About this color
#646B81 is a medium-dark, muted blue. In OKLCH its lightness is 53%, its chroma 0.036 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Metallic Blue (#4F738E), ΔE 0.034 away. White text reads best on it, at 5.30:1.
| Hue family | Blues |
| Lightness | medium-dark (53%) |
| Chroma | muted (0.036) |
| Temperature | cool |
| Nearest name | Metallic Blue (#4F738E) |
| Black text | 3.96:1 |
| White text | 5.30:1 |
Values
| HEX | #646B81 |
| RGB | rgb(100, 107, 129) |
| HSL | hsl(226, 13%, 45%) |
| OKLCH | oklch(53% 0.036 271.3) |
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 #646B81 | 5.30:1 | AA | Lc -81.7 | Fine for body text |
| Black text on #646B81 | 3.96:1 | AA large text | Lc 27.7 | Dividers and decoration only |
| #646B81 text on white | 5.30:1 | AA | Lc 76.4 | Fine for body text |
| #646B81 text on black | 3.96:1 | AA large text | Lc -25.4 | 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
#F5F5F7
oklch(97.1% 0.003 286.4)
-
Step 100
100
#E9EAED
oklch(93.7% 0.004 271.4)
-
Step 200
200
#D7D9DF
oklch(88.6% 0.008 271.3)
-
Step 300
300
#BDC0CB
oklch(80.9% 0.016 273.8)
-
Step 400
400
#9AA0B1
oklch(70.6% 0.026 270.2)
-
Step 500
500
#82899E
oklch(63.2% 0.033 270.9)
-
Step 600
600 (this color)
#646B81
oklch(53% 0.036 271.3)
-
Step 700
700
#5A6074
oklch(49.1% 0.033 272)
-
Step 800
800
#494E5E
oklch(42.6% 0.027 271.6)
-
Step 900
900
#3D414D
oklch(37.6% 0.021 270.8)
-
Step 950
950
#24262D
oklch(27% 0.013 272.9)
#646B81 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) | #656D82 | 0.006 |
| Deuteranopia (no green cones) | #626A80 | 0.004 |
| Tritanopia (no blue cones) | #5D6F72 | 0.032 |
| Achromatopsia (no color) | #6B6B6B | 0.036 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #646B81
#646B81
oklch(53% 0.036 271.3)
- #736B54
#736B54
oklch(52.9% 0.036 91.1)
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 #646B81, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Metallic Blue #4F738E ΔE 0.034
- Battleship Gray #6C757D ΔE 0.035
- Dim Gray #696969 ΔE 0.037
- Slate #516572 ΔE 0.040
- Grey Blue #647D8E ΔE 0.051
- Grey Purple #826D8C ΔE 0.051
- Dull Blue #49759C ΔE 0.051
- Battleship Grey #6B7C85 ΔE 0.051
Use #646B81 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.