Color
#310b65
#310b65rgb(49, 11, 101)hsl(265, 80%, 22%)oklch(0.281 0.14 294.2)Colors that go with #310b65
Charcoal, Royal Blue and Cobalt 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 #310b65: softer than #000 and cool enough to feel like part of the same palette.
Royal Blue #4169e1
analogousshippedRoyal Blue is #310b65'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 #310b65: 6 real palettes, including Blue Mono and Purina Pro Plan's brand system, as the lead colour.
Crimson #dc143c
shippedCrimson is paired with #310b65 in 5 real palettes, including Casper Sleep's brand system and Nintendo's brand system, as the lead colour.
Denim #1560bd
shippedDesigners have shipped Denim with #310b65: 10 real palettes, including Bank of America's brand system and Discover's brand system, as the accent.
Powder Blue #b0e0e6
shippedDesigners have shipped Powder Blue with #310b65: 4 real palettes, including Glacier and First Snow, as the supporting colour.
Steel Blue #4682b4
shippedDesigners have shipped Steel Blue with #310b65: 7 real palettes, including Deep Water and Glacier, as the supporting colour.
Tomato #ff6347
shipped4 real palettes, including FedEx's brand system and dbt Labs's brand system put Tomato beside #310b65, as the supporting colour.
Real palettes that use #310b65
Tints & shades
Harmonies
Contrast
| #310b65 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 15.37:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.37:1 | 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 #310b65 as the background.
Brands using this color
Fonts for this mood
#310b65 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 #310b65 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/310b65-b19cc4-dfd54e-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