Color

#3151af

#3151af
hex#3151af
rgbrgb(49, 81, 175)
hslhsl(225, 56%, 44%)
oklchoklch(0.466 0.155 266.3)
Closest name: Blasphemous Blue (#3356aa)Relative luminance 0.0963

Colors that go with #3151af

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 →

#af9031

#3190af · #5131af

#af3151 · #51af31

Split-complementary

Open in tool →

#af5131 · #90af31

#af3190 · #af9031 · #31af51

Contrast

#3151af as textRatioAAAA largeAAAFix
Aaon white
7.18:1passpasspassPasses AAA — no fix needed.
Aaon black
2.93:1failfailfail
  • AA: use #506fce as the text (4.51:1)
  • AAA: use #7c93da as the text (7.04:1)
  • AA: or shift the background to #cfcfcf (4.61:1)
  • AAA: or shift the background to #ffffff (7.18:1)

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

Brands using this color

Fonts for this mood

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

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

tool url/palettes/new/3151af-9ca1c4-df754e-221f2d-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