Color

#313eb4

#313eb4
hex#313eb4
rgbrgb(49, 62, 180)
hslhsl(234, 57%, 45%)
oklchoklch(0.434 0.185 271.3)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0739

Colors that go with #313eb4

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 →

#b4a731

#3180b4 · #6631b4

#b4313e · #3eb431

Split-complementary

Open in tool →

#b46631 · #80b431

#b43180 · #b4a731 · #31b466

Contrast

#313eb4 as textRatioAAAA largeAAAFix
Aaon white
8.47:1passpasspassPasses AAA — no fix needed.
Aaon black
2.48:1failfailfail
  • AA: use #636ed4 as the text (4.71:1)
  • AAA: use #8790de as the text (7.07:1)
  • AA: or shift the background to #bdbdbd (4.51:1)
  • AAA: or shift the background to #ebebeb (7.11:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #313eb4 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

#313eb4 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #313eb4
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 #313eb4 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/313eb4-9d9cc4-df8a4e-241f2d-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