Color

#1c3eba

#1c3eba
hex#1c3eba
rgbrgb(28, 62, 186)
hslhsl(227, 74%, 42%)
oklchoklch(0.431 0.198 265.8)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0724

Colors that go with #1c3eba

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.

Real palettes that use #1c3eba

Tints & shades

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

Harmonies

Complementary

Open in tool →

#ba981c

#1c8dba · #491cba

#ba1c3e · #3eba1c

Split-complementary

Open in tool →

#ba491c · #8dba1c

#ba1c8d · #ba981c · #1cba49

Contrast

#1c3eba as textRatioAAAA largeAAAFix
Aaon white
8.58:1passpasspassPasses AAA — no fix needed.
Aaon black
2.45:1failfailfail
  • AA: use #496be4 as the text (4.51:1)
  • AAA: use #7a92eb as the text (7.14:1)
  • AA: or shift the background to #bdbdbd (4.57:1)
  • AAA: or shift the background to #e8e8e8 (7:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1c3eba as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#1c3eba reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1c3eba
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 #1c3eba and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1c3eba-9ca0c4-df7a4e-221f2d-e9eff1?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