#666C87
Closest named color: Metallic Blue (#4F738E). oklch(53.6% 0.043 275.1), rgb(102, 108, 135).
Aa
White text reads best on this color (5.17:1).
About this color
#666C87 is a medium-dark, muted blue. In OKLCH its lightness is 54%, its chroma 0.043 and its hue 275°. Its hue sits on the cool side of the wheel. The nearest named color is Metallic Blue (#4F738E), ΔE 0.033 away. White text reads best on it, at 5.17:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | muted (0.043) |
| Temperature | cool |
| Nearest name | Metallic Blue (#4F738E) |
| Black text | 4.05:1 |
| White text | 5.17:1 |
Values
| HEX | #666C87 |
| RGB | rgb(102, 108, 135) |
| HSL | hsl(229, 14%, 46%) |
| OKLCH | oklch(53.6% 0.043 275.1) |
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 #666C87 | 5.17:1 | AA | Lc -81.0 | Fine for body text |
| Black text on #666C87 | 4.05:1 | AA large text | Lc 28.4 | Dividers and decoration only |
| #666C87 text on white | 5.17:1 | AA | Lc 75.6 | Fine for body text |
| #666C87 text on black | 4.05:1 | AA large text | Lc -26.1 | 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
#E9EAEE
oklch(93.7% 0.005 275)
-
Step 200
200
#D7D9E0
oklch(88.6% 0.01 273.3)
-
Step 300
300
#BDC0CD
oklch(80.9% 0.018 275.6)
-
Step 400
400
#9B9FB4
oklch(70.6% 0.031 277)
-
Step 500
500
#8288A2
oklch(63.1% 0.04 275)
-
Step 600
600 (this color)
#666C87
oklch(53.6% 0.043 275.1)
-
Step 700
700
#5A5F78
oklch(49.1% 0.041 276)
-
Step 800
800
#494E61
oklch(42.7% 0.032 273.4)
-
Step 900
900
#3D4150
oklch(37.8% 0.026 273.4)
-
Step 950
950
#24262F
oklch(27% 0.017 275.4)
#666C87 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) | #646E88 | 0.006 |
| Deuteranopia (no green cones) | #626C86 | 0.006 |
| Tritanopia (no blue cones) | #5E7175 | 0.039 |
| Achromatopsia (no color) | #6D6D6D | 0.043 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #666C87
#666C87
oklch(53.6% 0.043 275.1)
- #756E51
#756E51
oklch(53.7% 0.044 96.1)
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 #666C87, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Metallic Blue #4F738E ΔE 0.033
- Battleship Gray #6C757D ΔE 0.037
- Grey Purple #826D8C ΔE 0.045
- Dim Gray #696969 ΔE 0.046
- Dull Blue #49759C ΔE 0.047
- Grey Blue #647D8E ΔE 0.048
- Slate #516572 ΔE 0.049
- Battleship Grey #6B7C85 ΔE 0.050
Use #666C87 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.