Color

#31439b

#31439b
hex#31439b
rgbrgb(49, 67, 155)
hslhsl(230, 52%, 40%)
oklchoklch(0.422 0.145 270.3)
Closest name: Cascade Twilight (#234893)Relative luminance 0.0703

Colors that go with #31439b

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 →

#9b8931

#31789b · #54319b

#9b3143 · #439b31

Split-complementary

Open in tool →

#9b5431 · #789b31

#9b3178 · #9b8931 · #319b54

Contrast

#31439b as textRatioAAAA largeAAAFix
Aaon white
8.73:1passpasspassPasses AAA — no fix needed.
Aaon black
2.41:1failfailfail
  • AA: use #5c6fcc as the text (4.6:1)
  • AAA: use #8391d8 as the text (7.01:1)
  • AA: or shift the background to #bdbdbd (4.64:1)
  • AAA: or shift the background to #e8e8e8 (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 #31439b as the background.

Brands using this color

Fonts for this mood

#31439b reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #31439b
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 #31439b and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/31439b-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