Color

#153fbc

#153fbc
hex#153fbc
rgbrgb(21, 63, 188)
hslhsl(225, 80%, 41%)
oklchoklch(0.432 0.201 264.5)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0735

Colors that go with #153fbc

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 #153fbc

Tints & shades

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

Harmonies

Complementary

Open in tool →

#bc9215

#1592bc · #3f15bc

#bc153f · #3fbc15

Split-complementary

Open in tool →

#bc3f15 · #92bc15

#bc1592 · #bc9215 · #15bc3f

Contrast

#153fbc as textRatioAAAA largeAAAFix
Aaon white
8.51:1passpasspassPasses AAA — no fix needed.
Aaon black
2.47:1failfailfail
  • AA: use #436dea as the text (4.61:1)
  • AAA: use #7594f0 as the text (7.25:1)
  • AA: or shift the background to #bdbdbd (4.53:1)
  • AAA: or shift the background to #ebebeb (7.13:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #153fbc as the background.

Brands using this color

Fonts for this mood

#153fbc reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #153fbc
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 #153fbc and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/153fbc-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