Color

#3f587d

#3f587d
hex#3f587d
rgbrgb(63, 88, 125)
hslhsl(216, 33%, 37%)
oklchoklch(0.457 0.068 258)
Closest name: Deep Indigo (#4c567a)Relative luminance 0.0952

Tints & shades

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

Harmonies

Complementary

Open in tool →

#7d653f

#3f777d · #453f7d

#7d3f58 · #587d3f

Split-complementary

Open in tool →

#7d453f · #777d3f

#7d3f77 · #7d653f · #3f7d45

Contrast

#3f587d as textRatioAAAA largeAAAFix
Aaon white
7.23:1passpasspassPasses AAA — no fix needed.
Aaon black
2.9:1failfailfail
  • AA: use #5577aa as the text (4.61:1)
  • AAA: use #7e98be as the text (7.12:1)
  • AA: or shift the background to #cccccc (4.5:1)
  • AAA: or shift the background to #fcfcfc (7.05:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f587d as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

mcpConnect your agent — build around #3f587d
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 #3f587d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f587d-9ca7c4-df5f4e-201f2d-e9f0f1?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