Color
#431b8d
#431b8drgb(67, 27, 141)hsl(261, 68%, 33%)oklch(0.36 0.171 291.1)Colors that go with #431b8d
Royal Blue, Charcoal and Denim 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 #431b8d's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Charcoal #36454f
neutralshippedCharcoal is the text near-black for #431b8d: softer than #000 and cool enough to feel like part of the same palette.
Denim #1560bd
shippedDesigners have shipped Denim with #431b8d: 6 real palettes, including Google's brand system and Slack's brand system, as the accent.
Olive Green #808000
complementaryOlive Green sits directly opposite #431b8d on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Blue #0000ff
shipped3 real palettes, including Zillow's brand system and Pepsi's brand system put Blue beside #431b8d, as the lead colour.
Crimson #dc143c
shippedCrimson is paired with #431b8d in 3 real palettes, including Casper Sleep's brand system and Marvel's brand system, as the lead colour.
Steel Blue #4682b4
shippedDesigners have shipped Steel Blue with #431b8d: 3 real palettes, including Hershey's's brand system and Fintech Trust, as the accent.
Taupe #483c32
shippedTaupe is paired with #431b8d in 3 real palettes, including Datadog's brand system and Gillette's brand system, as that palette's text colour.
Real palettes that use #431b8d
Tints & shades
Harmonies
Contrast
| #431b8d as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 11.8:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.78:1 | 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 #431b8d 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
#431b8d 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 #431b8d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/431b8d-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