Color

#133db9

#133db9
hex#133db9
rgbrgb(19, 61, 185)
hslhsl(225, 81%, 40%)
oklchoklch(0.425 0.199 264.4)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0698

Colors that go with #133db9

Charcoal, Sea Green 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.

Real palettes that use #133db9

Tints & shades

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

Harmonies

Complementary

Open in tool →

#b98f13

#138fb9 · #3d13b9

#b9133d · #3db913

Split-complementary

Open in tool →

#b93d13 · #8fb913

#b9138f · #b98f13 · #13b93d

Contrast

#133db9 as textRatioAAAA largeAAAFix
Aaon white
8.77:1passpasspassPasses AAA — no fix needed.
Aaon black
2.4:1failfailfail
  • AA: use #426ceb as the text (4.58:1)
  • AAA: use #7594f0 as the text (7.25:1)
  • AA: or shift the background to #bababa (4.52:1)
  • AAA: or shift the background to #e6e6e6 (7.02:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #133db9 as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#133db9 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #133db9
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 #133db9 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/133db9-9ca1c4-df754e-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