Color

#1d66aa

#1d66aa
hex#1d66aa
rgbrgb(29, 102, 170)
hslhsl(209, 71%, 39%)
oklchoklch(0.502 0.129 251)
Closest name: Denim (#1560bd)Relative luminance 0.1267

Colors that go with #1d66aa

Charcoal, Crimson and Sienna 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 →

#aa611d

#1daaa8 · #1d1faa

#aa1d66 · #66aa1d

Split-complementary

Open in tool →

#aa1d1f · #aaa81d

#a81daa · #aa611d · #1faa1d

Contrast

#1d66aa as textRatioAAAA largeAAAFix
Aaon white
5.94:1passpassfail
  • AAA: use #195994 as the text (7.25:1)
Aaon black
3.53:1failpassfail
  • AA: use #2278c9 as the text (4.6:1)
  • AAA: use #519be1 as the text (7.13:1)
  • AA: or shift the background to #e0e0e0 (4.5:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1d66aa as the background.

Brands using this color

Fonts for this mood

#1d66aa reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1d66aa
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 #1d66aa and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1d66aa-9cacc4-df4e4e-1f212d-e9f1f1?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