Color
#663fcf
#663fcfrgb(102, 63, 207)hsl(256, 60%, 53%)oklch(0.5 0.208 289)Colors that go with #663fcf
Charcoal, Royal Blue and Sea 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 #663fcf: softer than #000 and cool enough to feel like part of the same palette.
Royal Blue #4169e1
analogousshippedRoyal Blue is #663fcf's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Sea Green #2e8b57
split-complementshippedSea Green is a split-complement of #663fcf: nearly opposite, so it still pops against it, without the vibrating edge of a true complement.
Amber #ffbf00
shippedAmber is paired with #663fcf in 5 real palettes, including Warner Bros.'s brand system and Wikipedia's brand system, as the accent.
Blue #0000ff
shipped4 real palettes, including Zillow's brand system and Pixar's brand system put Blue beside #663fcf, as the lead colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #663fcf: 6 real palettes, including Zillow's brand system and Warbyparker's brand system, as the supporting colour.
Cornflower Blue #6495ed
shippedDesigners have shipped Cornflower Blue with #663fcf: 7 real palettes, including Coca-Cola's brand system and Mastodon hosted on mastodon.social's brand system, as the supporting colour.
Crimson #dc143c
shippedCrimson is paired with #663fcf in 10 real palettes, including Gemstone and Wells Fargo's brand system, as the accent.
Real palettes that use #663fcf
Tints & shades
Harmonies
Contrast
| #663fcf as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 6.61:1 | pass | pass | fail |
|
Aaon black | 3.18:1 | 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 #663fcf as the background.
Brands using this color
No public brand in the corpus uses this exact color yet. Extract a brand to add one.
Fonts for this mood
#663fcf reads as cool, vivid, technical. The font library is tagged with the same vocabulary:
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 #663fcf and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/663fcf-ab9cc4-dfbf4e-291f2d-e9ebf1?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