Color

#2131ab

#2131ab
hex#2131ab
rgbrgb(33, 49, 171)
hslhsl(233, 68%, 40%)
oklchoklch(0.395 0.192 268.8)
Closest name: Blue Hour (#0034ab)Relative luminance 0.0546

Colors that go with #2131ab

Charcoal, Steel Blue and 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.

Tints & shades

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

Harmonies

Complementary

Open in tool →

#ab9b21

#2176ab · #5621ab

#ab2131 · #31ab21

Split-complementary

Open in tool →

#ab5621 · #76ab21

#ab2176 · #ab9b21 · #21ab56

Contrast

#2131ab as textRatioAAAA largeAAAFix
Aaon white
10.04:1passpasspassPasses AAA — no fix needed.
Aaon black
2.09:1failfailfail
  • AA: use #5c6ce0 as the text (4.68:1)
  • AAA: use #8792e8 as the text (7.31:1)
  • AA: or shift the background to #b0b0b0 (4.63:1)
  • AAA: or shift the background to #d9d9d9 (7.11:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #2131ab 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

#2131ab reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #2131ab
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 #2131ab and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/2131ab-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