Color
#511a99
#511a99rgb(81, 26, 153)hsl(266, 71%, 35%)oklch(0.386 0.186 295.7)Colors that go with #511a99
Royal Blue, Cobalt Blue and Crimson 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.
Royal Blue #4169e1
analogousshippedRoyal Blue is #511a99's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #511a99: 4 real palettes, including Zillow's brand system and Unilever's brand system, as the supporting colour.
Crimson #dc143c
shippedCrimson is paired with #511a99 in 4 real palettes, including Wells Fargo's brand system and Walgreens's brand system, as the lead colour.
Denim #1560bd
shippedDesigners have shipped Denim with #511a99: 4 real palettes, including Slack's brand system and Warbyparker's brand system, as the lead colour.
Midnight Blue #191970
shipped5 real palettes, including Kraken's brand system and Blue Mono put Midnight Blue beside #511a99, as the lead colour.
Steel Blue #4682b4
shippedDesigners have shipped Steel Blue with #511a99: 4 real palettes, including FedEx's brand system and Hershey's's brand system, as the accent.
Olive Green #808000
complementaryOlive Green sits directly opposite #511a99 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Charcoal #36454f
neutralshippedCharcoal is the text near-black for #511a99: softer than #000 and cool enough to feel like part of the same palette.
Real palettes that use #511a99
Tints & shades
Harmonies
Contrast
| #511a99 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 10.73:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.96:1 | 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 #511a99 as the background.
Brands using this color
Fonts for this mood
#511a99 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 #511a99 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/511a99-b29cc4-dfd74e-2b1f2d-e9eaf1?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