Color

#3151a0

#3151a0
hex#3151a0
rgbrgb(49, 81, 160)
hslhsl(223, 53%, 41%)
oklchoklch(0.455 0.134 265)
Closest name: Blasphemous Blue (#3356aa)Relative luminance 0.0908

Colors that go with #3151a0

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 →

#a08131

#3188a0 · #4931a0

#a03151 · #51a031

Split-complementary

Open in tool →

#a04931 · #88a031

#a03188 · #a08131 · #31a049

Contrast

#3151a0 as textRatioAAAA largeAAAFix
Aaon white
7.46:1passpasspassPasses AAA — no fix needed.
Aaon black
2.82:1failfailfail
  • AA: use #4f72c9 as the text (4.58:1)
  • AAA: use #7a94d6 as the text (7.03:1)
  • AA: or shift the background to #c9c9c9 (4.5:1)
  • AAA: or shift the background to #fafafa (7.15:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3151a0 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

#3151a0 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3151a0
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 #3151a0 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3151a0-9ca3c4-df704e-211f2d-e9eff1?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