Color

#3131aa

#3131aa
hex#3131aa
rgbrgb(49, 49, 170)
hslhsl(240, 55%, 43%)
oklchoklch(0.403 0.187 274.1)
Closest name: Depths of Night (#2c319b)Relative luminance 0.0575

Colors that go with #3131aa

Charcoal, Sea Green and Steel 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 →

#aaaa31

#316eaa · #6e31aa

#aa3131 · #31aa31

Split-complementary

Open in tool →

#aa6e31 · #6eaa31

#aa316e · #aaaa31 · #31aa6e

Contrast

#3131aa as textRatioAAAA largeAAAFix
Aaon white
9.77:1passpasspassPasses AAA — no fix needed.
Aaon black
2.15:1failfailfail
  • AA: use #6969d3 as the text (4.56:1)
  • AAA: use #9090df as the text (7.24:1)
  • AA: or shift the background to #b0b0b0 (4.5:1)
  • AAA: or shift the background to #dbdbdb (7.05:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3131aa 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

#3131aa reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3131aa
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 #3131aa and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3131aa-a19cc4-df994e-251f2d-e9edf1?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