Color

#1f4fb7

#1f4fb7
hex#1f4fb7
rgbrgb(31, 79, 183)
hslhsl(221, 71%, 42%)
oklchoklch(0.461 0.173 262.9)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.093

Colors that go with #1f4fb7

Charcoal, Steel Blue 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 →

#b7871f

#1f9bb7 · #3b1fb7

#b71f4f · #4fb71f

Split-complementary

Open in tool →

#b73b1f · #9bb71f

#b71f9b · #b7871f · #1fb73b

Contrast

#1f4fb7 as textRatioAAAA largeAAAFix
Aaon white
7.34:1passpasspassPasses AAA — no fix needed.
Aaon black
2.86:1failfailfail
  • AA: use #3f72de as the text (4.67:1)
  • AAA: use #6f95e7 as the text (7.13:1)
  • AA: or shift the background to #cccccc (4.57:1)
  • AAA: or shift the background to #fafafa (7.03:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1f4fb7 as the background.

Brands using this color

Fonts for this mood

#1f4fb7 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1f4fb7
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 #1f4fb7 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1f4fb7-9ca4c4-df6b4e-211f2d-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