Color

#1f37ef

#1f37ef
hex#1f37ef
rgbrgb(31, 55, 239)
hslhsl(233, 87%, 53%)
oklchoklch(0.477 0.267 266.7)
Closest name: C64 Blue (#003aff)Relative luminance 0.0926

Colors that go with #1f37ef

Charcoal, Crimson 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 →

#efd71f

#1f9fef · #6f1fef

#ef1f37 · #37ef1f

Split-complementary

Open in tool →

#ef6f1f · #9fef1f

#ef1f9f · #efd71f · #1fef6f

Contrast

#1f37ef as textRatioAAAA largeAAAFix
Aaon white
7.37:1passpasspassPasses AAA — no fix needed.
Aaon black
2.85:1failfailfail
  • AA: use #5366f3 as the text (4.56:1)
  • AAA: use #8390f6 as the text (7.29:1)
  • AA: or shift the background to #cccccc (4.59:1)
  • AAA: or shift the background to #fafafa (7.06:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1f37ef as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#1f37ef reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1f37ef
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 #1f37ef and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1f37ef-9c9cc4-df884e-241f2d-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