Color
#591dc9
#591dc9rgb(89, 29, 201)hsl(261, 75%, 45%)oklch(0.446 0.233 288.4)Colors that go with #591dc9
Charcoal, Royal Blue and Midnight 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 #591dc9: softer than #000 and cool enough to feel like part of the same palette.
Royal Blue #4169e1
analogousshippedRoyal Blue is #591dc9's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Midnight Blue #191970
shipped4 real palettes, including Kraken's brand system and Purina Pro Plan's brand system put Midnight Blue beside #591dc9, as the lead colour.
Olive Green #808000
complementaryOlive Green sits directly opposite #591dc9 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Cornflower Blue #6495ed
shippedDesigners have shipped Cornflower Blue with #591dc9: 3 real palettes, including Qualcomm's brand system and Blue Mono, as the supporting colour.
Denim #1560bd
shippedDesigners have shipped Denim with #591dc9: 3 real palettes, including Intel's brand system and Pixar's brand system, as the supporting colour.
Orange Red #ff4500
shippedOrange Red is paired with #591dc9 in 3 real palettes, including Prepare your taste buds...'s brand system and Soundcloud's brand system, as the lead colour.
Slate Gray #708090
shipped3 real palettes, including Indigo SaaS and Ink & Paper put Slate Gray beside #591dc9, as the supporting colour.
Real palettes that use #591dc9
Tints & shades
Harmonies
Contrast
| #591dc9 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 8.59:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.44:1 | 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 #591dc9 as the background.
Brands using this color
Fonts for this mood
#591dc9 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 #591dc9 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/591dc9-af9cc4-dfcb4e-2a1f2d-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