Color
#666d8f
#666d8frgb(102, 109, 143)hsl(230, 17%, 48%)oklch(0.542 0.054 275.4)Colors that go with #666d8f
Charcoal, Sea Green and Dark Olive Green lead the list. Each partner is a real named colour with the reason it works — a wheel relationship, a neutral that carries it, or a pairing lifted from a palette or brand system that actually shipped — and every pair opens in the palette tool.
Charcoal #36454f
neutralshippedCharcoal is the text near-black for #666d8f: softer than #000 and cool enough to feel like part of the same palette.
Sea Green #2e8b57
triadicshippedSea Green completes a triad with #666d8f — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Dark Olive Green #556b2f
complementaryshippedDark Olive Green sits directly opposite #666d8f on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Amber #ffbf00
shippedAmber is paired with #666d8f in 5 real palettes, including Beach Hut and Lemon Squeezy's brand system, as the supporting colour.
Champagne #f7e7ce
shipped6 real palettes, including Midnight Luxe and Coffee Bar put Champagne beside #666d8f, as that palette's text colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #666d8f: 6 real palettes, including Fintech Trust and Ink & Paper, as the lead colour.
Copper #b87333
shippedDesigners have shipped Copper with #666d8f: 6 real palettes, including Dusk and Riverbed, as the accent.
Crimson #dc143c
shippedCrimson is paired with #666d8f in 8 real palettes, including Retro Pop and Marvel's brand system, as the lead colour.
Real palettes that use #666d8f
Tints & shades
Harmonies
Contrast
| #666d8f as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 5.06:1 | pass | pass | fail |
|
Aaon black | 4.15:1 | fail | pass | fail |
Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #666d8f as the background.
Brands using this color
No public brand in the corpus uses this exact color yet. Extract a brand to add one.
Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — direct_palette, edit_direction, check_palette, check_contrast — read-only, no key. Every direction it proposes comes with a /colors/d/… link: open it, lock what you like, paste the link back, and the agent edits rather than re-rolls.
https://mcp.brandsweets.com/colors/mcpclaude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
›analyze #666d8f and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/666d8f-9c9ec4-df814e-231f2d-e9eef1?lock=0&style=vibrantWant the agent to remember your picks and write them into a living brand? Create a free BrandSweets workspace.
Machine-readable: color.md