Color

#2a51df

#2a51df
hex#2a51df
rgbrgb(42, 81, 223)
hslhsl(227, 74%, 52%)
oklchoklch(0.504 0.22 266.2)
Closest name: Arcane Brew (#5260e1)Relative luminance 0.117

Colors that go with #2a51df

Charcoal, Sea Green 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.

Real palettes that use #2a51df

Tints & shades

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

Harmonies

Complementary

Open in tool →

#dfb82a

#2aacdf · #5d2adf

#df2a51 · #51df2a

Split-complementary

Open in tool →

#df5d2a · #acdf2a

#df2aac · #dfb82a · #2adf5d

Contrast

#2a51df as textRatioAAAA largeAAAFix
Aaon white
6.29:1passpassfail
  • AAA: use #2047d5 as the text (7.18:1)
Aaon black
3.34:1failpassfail
  • AA: use #496be4 as the text (4.51:1)
  • AAA: use #7a92eb as the text (7.14:1)
  • AA: or shift the background to #dbdbdb (4.54:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #2a51df as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#2a51df reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #2a51df
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 #2a51df and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/2a51df-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