Color

#1d3cc3

#1d3cc3
hex#1d3cc3
rgbrgb(29, 60, 195)
hslhsl(229, 74%, 44%)
oklchoklch(0.437 0.211 266.3)
Closest name: Lapis on Neptune (#1f22d2)Relative luminance 0.0743

Colors that go with #1d3cc3

Charcoal, Sea Green 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 →

#c3a51d

#1d8fc3 · #521dc3

#c31d3c · #3cc31d

Split-complementary

Open in tool →

#c3521d · #8fc31d

#c31d8f · #c3a51d · #1dc352

Contrast

#1d3cc3 as textRatioAAAA largeAAAFix
Aaon white
8.45:1passpasspassPasses AAA — no fix needed.
Aaon black
2.49:1failfailfail
  • AA: use #526de5 as the text (4.68:1)
  • AAA: use #7e92ec as the text (7.21:1)
  • AA: or shift the background to #bfbfbf (4.59:1)
  • AAA: or shift the background to #ebebeb (7.08:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1d3cc3 as the background.

Brands using this color

Fonts for this mood

#1d3cc3 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1d3cc3
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 #1d3cc3 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1d3cc3-9c9fc4-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