Color

#313f87

#313f87
hex#313f87
rgbrgb(49, 63, 135)
hslhsl(230, 47%, 36%)
oklchoklch(0.397 0.121 271.6)
Closest name: Evening Magic (#363e7d)Relative luminance 0.0596

Colors that go with #313f87

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.

Tints & shades

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

Harmonies

Complementary

Open in tool →

#877931

#316a87 · #4d3187

#87313f · #3f8731

Split-complementary

Open in tool →

#874d31 · #6a8731

#87316a · #877931 · #31874d

Contrast

#313f87 as textRatioAAAA largeAAAFix
Aaon white
9.58:1passpasspassPasses AAA — no fix needed.
Aaon black
2.19:1failfailfail
  • AA: use #5e6fc5 as the text (4.56:1)
  • AAA: use #8794d4 as the text (7.22:1)
  • AA: or shift the background to #b3b3b3 (4.57:1)
  • AAA: or shift the background to #dedede (7.12:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #313f87 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

#313f87 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #313f87
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 #313f87 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/313f87-9c9ec4-df814e-231f2d-e9eef1?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