Color

#310da5

#310da5
hex#310da5
rgbrgb(49, 13, 165)
hslhsl(254, 85%, 35%)
oklchoklch(0.357 0.209 278.1)
Closest name: Galactic Highway (#3311bb)Relative luminance 0.0366

Colors that go with #310da5

Blue, Cobalt Blue and Royal 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.

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#82a50d

#0d36a5 · #7d0da5

#a5310d · #0da531

Split-complementary

Open in tool →

#a57d0d · #36a50d

#a50d36 · #82a50d · #0da57d

Contrast

#310da5 as textRatioAAAA largeAAAFix
Aaon white
12.13:1passpasspassPasses AAA — no fix needed.
Aaon black
1.73:1failfailfail
  • AA: use #7d5af2 as the text (4.62:1)
  • AAA: use #9f84f5 as the text (7.09:1)
  • AA: or shift the background to #9e9e9e (4.53:1)
  • AAA: or shift the background to #c7c7c7 (7.17:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #310da5 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

#310da5 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #310da5
live endpoint

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.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #310da5 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/310da5-aa9cc4-dfbb4e-291f2d-e9ebf1?lock=0&style=vibrant

Want the agent to remember your picks and write them into a living brand? Create a free BrandSweets workspace.

Machine-readable: color.md