Color
#310d72
#310d72rgb(49, 13, 114)hsl(261, 80%, 25%)oklch(0.297 0.153 289.4)Colors that go with #310d72
Charcoal, Royal Blue and 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 #310d72: softer than #000 and cool enough to feel like part of the same palette.
Royal Blue #4169e1
analogousshippedRoyal Blue is #310d72's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Blue #0000ff
shipped4 real palettes, including Pepsi's brand system and Sketch's brand system put Blue beside #310d72, as the supporting colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #310d72: 4 real palettes, including Purina Pro Plan's brand system and Blue Mono, as the accent.
Crimson #dc143c
shippedCrimson is paired with #310d72 in 4 real palettes, including Casper Sleep's brand system and Nintendo's brand system, as the lead colour.
Denim #1560bd
shippedDesigners have shipped Denim with #310d72: 5 real palettes, including Bank of America's brand system and Discover's brand system, as the accent.
Steel Blue #4682b4
shippedDesigners have shipped Steel Blue with #310d72: 7 real palettes, including Deep Water and Glacier, as the supporting colour.
Olive Green #808000
complementaryOlive Green sits directly opposite #310d72 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Real palettes that use #310d72
Tints & shades
Harmonies
Contrast
| #310d72 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 14.67:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.43:1 | 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 #310d72 as the background.
Brands using this color
Fonts for this mood
#310d72 reads as cool, vivid, dark. 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 #310d72 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/310d72-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