Color

#3f65ab

#3f65ab
hex#3f65ab
rgbrgb(63, 101, 171)
hslhsl(219, 46%, 46%)
oklchoklch(0.513 0.12 261.6)
Closest name: Bellflower (#5d66aa)Relative luminance 0.133

Colors that go with #3f65ab

Charcoal, Sea Green and Amber 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 →

#ab853f

#3f9bab · #503fab

#ab3f65 · #65ab3f

Split-complementary

Open in tool →

#ab503f · #9bab3f

#ab3f9b · #ab853f · #3fab50

Contrast

#3f65ab as textRatioAAAA largeAAAFix
Aaon white
5.74:1passpassfail
  • AAA: use #375895 as the text (7.02:1)
Aaon black
3.66:1failpassfail
  • AA: use #4c74bd as the text (4.54:1)
  • AAA: use #7997cd as the text (7.12:1)
  • AA: or shift the background to #e6e6e6 (4.6:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f65ab 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

#3f65ab reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f65ab
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 #3f65ab and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f65ab-9ca5c4-df664e-211f2d-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