Color

#31378c

#31378c
hex#31378c
rgbrgb(49, 55, 140)
hslhsl(236, 48%, 37%)
oklchoklch(0.385 0.139 274.7)
Closest name: Bluebell (#333399)Relative luminance 0.0528

Colors that go with #31378c

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 →

#8c8631

#31648c · #58318c

#8c3137 · #378c31

Split-complementary

Open in tool →

#8c5831 · #648c31

#8c3164 · #8c8631 · #318c58

Contrast

#31378c as textRatioAAAA largeAAAFix
Aaon white
10.22:1passpasspassPasses AAA — no fix needed.
Aaon black
2.06:1failfailfail
  • AA: use #686fca as the text (4.72:1)
  • AAA: use #8e93d7 as the text (7.3:1)
  • AA: or shift the background to #adadad (4.55:1)
  • AAA: or shift the background to #d6d6d6 (7.03:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #31378c 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

#31378c reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #31378c
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 #31378c and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/31378c-9e9cc4-df8f4e-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