Color
#666c99
#666c99rgb(102, 108, 153)hsl(233, 20%, 50%)oklch(0.544 0.071 277.9)Colors that go with #666c99
Charcoal, Dark Olive Green and Amber 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 #666c99: softer than #000 and cool enough to feel like part of the same palette.
Dark Olive Green #556b2f
complementaryshippedDark Olive Green sits directly opposite #666c99 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 #666c99 in 6 real palettes, including Lemon Squeezy's brand system and Beach Hut, as the lead colour.
Champagne #f7e7ce
shipped4 real palettes, including Midnight Luxe and Coffee Bar put Champagne beside #666c99, as that palette's text colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #666c99: 7 real palettes, including Fintech Trust and Ink & Paper, as the lead colour.
Copper #b87333
shippedDesigners have shipped Copper with #666c99: 4 real palettes, including Dusk and Riverbed, as the accent.
Crimson #dc143c
shippedCrimson is paired with #666c99 in 15 real palettes, including Retro Pop and Marvel's brand system, as the lead colour.
Deep Sky Blue #00bfff
shippedDesigners have shipped Deep Sky Blue with #666c99: 5 real palettes, including Deep Water and Astro's brand system, as the lead colour.
Real palettes that use #666c99
Tints & shades
Harmonies
Contrast
| #666c99 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 5.04:1 | pass | pass | fail |
|
Aaon black | 4.17:1 | 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 #666c99 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 #666c99 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/666c99-9c9cc4-df884e-241f2d-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