Color

#0643ac

#0643ac
hex#0643ac
rgbrgb(6, 67, 172)
hslhsl(218, 93%, 35%)
oklchoklch(0.422 0.178 261.3)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0703

Colors that go with #0643ac

Charcoal, Crimson and Steel 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 →

#ac6f06

#0696ac · #1c06ac

#ac0643 · #43ac06

Split-complementary

Open in tool →

#ac1c06 · #96ac06

#ac0696 · #ac6f06 · #06ac1c

Contrast

#0643ac as textRatioAAAA largeAAAFix
Aaon white
8.73:1passpasspassPasses AAA — no fix needed.
Aaon black
2.41:1failfailfail
  • AA: use #1d6df7 as the text (4.58:1)
  • AAA: use #5d96f9 as the text (7.2:1)
  • AA: or shift the background to #bdbdbd (4.65:1)
  • AAA: or shift the background to #e8e8e8 (7.12:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #0643ac as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#0643ac reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #0643ac
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 #0643ac and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/0643ac-9ca6c4-df644e-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