Color
#666fa3
#666fa3rgb(102, 111, 163)hsl(231, 25%, 52%)oklch(0.556 0.082 275.9)Colors that go with #666fa3
Charcoal, Sea 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 #666fa3: softer than #000 and cool enough to feel like part of the same palette.
Sea Green #2e8b57
triadicshippedSea Green completes a triad with #666fa3 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Amber #ffbf00
shippedAmber is paired with #666fa3 in 8 real palettes, including Lemon Squeezy's brand system and Beach Hut, as the lead colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #666fa3: 7 real palettes, including Fintech Trust and Glacier, as the lead colour.
Copper #b87333
shippedDesigners have shipped Copper with #666fa3: 4 real palettes, including Dusk and Riverbed, as the accent.
Crimson #dc143c
shippedCrimson is paired with #666fa3 in 15 real palettes, including Marvel's brand system and Retro Pop, as the accent.
Deep Sky Blue #00bfff
shippedDesigners have shipped Deep Sky Blue with #666fa3: 5 real palettes, including Astro's brand system and Deep Water, as the supporting colour.
Denim #1560bd
shippedDesigners have shipped Denim with #666fa3: 14 real palettes, including Campus and The New York Times's brand system, as the lead colour.
Real palettes that use #666fa3
Tints & shades
Harmonies
Contrast
| #666fa3 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 4.81:1 | pass | pass | fail |
|
Aaon black | 4.37:1 | 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 #666fa3 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 #666fa3 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/666fa3-9c9ec4-df834e-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