Color

#3f445a

#3f445a
hex#3f445a
rgbrgb(63, 68, 90)
hslhsl(229, 18%, 30%)
oklchoklch(0.391 0.038 274.6)
Closest name: Bonne Nuit (#3a4866)Relative luminance 0.0593

Tints & shades

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

Harmonies

Complementary

Open in tool →

#5a553f

#3f525a · #473f5a

#5a3f44 · #445a3f

Split-complementary

Open in tool →

#5a473f · #525a3f

#5a3f52 · #5a553f · #3f5a47

Contrast

#3f445a as textRatioAAAA largeAAAFix
Aaon white
9.61:1passpasspassPasses AAA — no fix needed.
Aaon black
2.19:1failfailfail
  • AA: use #6c7499 as the text (4.6:1)
  • AAA: use #9096b2 as the text (7.19:1)
  • AA: or shift the background to #b3b3b3 (4.58:1)
  • AAA: or shift the background to #dedede (7.14:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f445a 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

#3f445a reads as cool, muted, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f445a
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 #3f445a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f445a-9c9fc4-df7e4e-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