Color

#3131a5

#3131a5
hex#3131a5
rgbrgb(49, 49, 165)
hslhsl(240, 54%, 42%)
oklchoklch(0.398 0.18 274.5)
Closest name: Depths of Night (#2c319b)Relative luminance 0.0557

Colors that go with #3131a5

Charcoal, Steel 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.

Real palettes that use #3131a5

Tints & shades

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

Harmonies

Complementary

Open in tool →

#a5a531

#316ba5 · #6b31a5

#a53131 · #31a531

Split-complementary

Open in tool →

#a56b31 · #6ba531

#a5316b · #a5a531 · #31a56b

Contrast

#3131a5 as textRatioAAAA largeAAAFix
Aaon white
9.94:1passpasspassPasses AAA — no fix needed.
Aaon black
2.11:1failfailfail
  • AA: use #6a6ad2 as the text (4.61:1)
  • AAA: use #9191de as the text (7.31:1)
  • AA: or shift the background to #b0b0b0 (4.58:1)
  • AAA: or shift the background to #d9d9d9 (7.04:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3131a5 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

#3131a5 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3131a5
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 #3131a5 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3131a5-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