Color
#663a88
#663a88rgb(102, 58, 136)hsl(274, 40%, 38%)oklch(0.439 0.129 308)Colors that go with #663a88
Charcoal, Midnight Blue and Royal Blue 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 #663a88: softer than #000 and cool enough to feel like part of the same palette.
Midnight Blue #191970
shipped4 real palettes, including Kraken's brand system and First Snow put Midnight Blue beside #663a88, as the lead colour.
Royal Blue #4169e1
shippedRoyal Blue is paired with #663a88 in 5 real palettes, including Wayfair's brand system and Console Light, as the supporting colour.
Tomato #ff6347
shipped6 real palettes, including Golden Hour and FedEx's brand system put Tomato beside #663a88, as the supporting colour.
Dark Olive Green #556b2f
complementaryDark Olive Green sits directly opposite #663a88 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Crimson #dc143c
shippedCrimson is paired with #663a88 in 3 real palettes, including Wells Fargo's brand system and Lenovo's brand system, as the lead colour.
Denim #1560bd
shippedDesigners have shipped Denim with #663a88: 3 real palettes, including Hinge's brand system and Slack's brand system, as the accent.
Taupe #483c32
shippedTaupe is paired with #663a88 in 3 real palettes, including Datadog's brand system and Superhuman's brand system, as that palette's text colour.
Real palettes that use #663a88
Tints & shades
Harmonies
Contrast
| #663a88 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 8.31:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.53:1 | fail | fail | fail |
Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #663a88 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
#663a88 reads as cool, modern. 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 #663a88 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/663a88-b79cc4-c2cb62-2d1f2d-eae9f1?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