Color

#133fa4

#133fa4
hex#133fa4
rgbrgb(19, 63, 164)
hslhsl(222, 79%, 36%)
oklchoklch(0.409 0.17 263.2)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0637

Colors that go with #133fa4

Charcoal, Crimson and Steel 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 →

#a47913

#1387a4 · #3013a4

#a4133f · #3fa413

Split-complementary

Open in tool →

#a43013 · #87a413

#a41387 · #a47913 · #13a430

Contrast

#133fa4 as textRatioAAAA largeAAAFix
Aaon white
9.23:1passpasspassPasses AAA — no fix needed.
Aaon black
2.27:1failfailfail
  • AA: use #3b6fe8 as the text (4.62:1)
  • AAA: use #6d94ee as the text (7.12:1)
  • AA: or shift the background to #b5b5b5 (4.5:1)
  • AAA: or shift the background to #e3e3e3 (7.19:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #133fa4 as the background.

Brands using this color

Fonts for this mood

#133fa4 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #133fa4
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 #133fa4 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/133fa4-9ca3c4-df6e4e-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