Color

#313b77

#313b77
hex#313b77
rgbrgb(49, 59, 119)
hslhsl(231, 42%, 33%)
oklchoklch(0.377 0.102 273.4)
Closest name: Evening Magic (#363e7d)Relative luminance 0.0511

Tints & shades

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

Harmonies

Complementary

Open in tool →

#776d31

#315f77 · #4a3177

#77313b · #3b7731

Split-complementary

Open in tool →

#774a31 · #5f7731

#77315f · #776d31 · #31774a

Contrast

#313b77 as textRatioAAAA largeAAAFix
Aaon white
10.38:1passpasspassPasses AAA — no fix needed.
Aaon black
2.02:1failfailfail
  • AA: use #6371bf as the text (4.64:1)
  • AAA: use #8892ce as the text (7.05:1)
  • AA: or shift the background to #ababab (4.52:1)
  • AAA: or shift the background to #d4d4d4 (7:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #313b77 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

#313b77 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #313b77
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — generate_palette, check_contrast, analyze_color — read-only, no key. Every palette it proposes comes with a /palettes/new/… link: open it, lock what you like, paste the link back.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #313b77 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/313b77-9c9ec4-df834e-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