Color

#1a37ef

#1a37ef
hex#1a37ef
rgbrgb(26, 55, 239)
hslhsl(232, 87%, 52%)
oklchoklch(0.475 0.268 266)
Closest name: C64 Blue (#003aff)Relative luminance 0.0918

Colors that go with #1a37ef

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 →

#efd31a

#1aa1ef · #681aef

#ef1a37 · #37ef1a

Split-complementary

Open in tool →

#ef681a · #a1ef1a

#ef1aa1 · #efd31a · #1aef68

Contrast

#1a37ef as textRatioAAAA largeAAAFix
Aaon white
7.4:1passpasspassPasses AAA — no fix needed.
Aaon black
2.84:1failfailfail
  • AA: use #5369f3 as the text (4.68:1)
  • AAA: use #7e8ef6 as the text (7.09:1)
  • AA: or shift the background to #cccccc (4.61:1)
  • AAA: or shift the background to #fafafa (7.09:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1a37ef 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

#1a37ef reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1a37ef
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 #1a37ef and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1a37ef-9c9dc4-df864e-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