Color

#03599b

#03599b
hex#03599b
rgbrgb(3, 89, 155)
hslhsl(206, 96%, 31%)
oklchoklch(0.457 0.128 250.2)
Closest name: Blue Chip (#1d5699)Relative luminance 0.0953

Colors that go with #03599b

Charcoal, Crimson and Sienna 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 →

#9b4503

#039b91 · #030d9b

#9b0359 · #599b03

Split-complementary

Open in tool →

#9b030d · #9b9103

#91039b · #9b4503 · #0d9b03

Contrast

#03599b as textRatioAAAA largeAAAFix
Aaon white
7.23:1passpasspassPasses AAA — no fix needed.
Aaon black
2.91:1failfailfail
  • AA: use #0479d2 as the text (4.67:1)
  • AAA: use #1e9bfa as the text (7.12:1)
  • AA: or shift the background to #cfcfcf (4.64:1)
  • AAA: or shift the background to #fcfcfc (7.04:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #03599b as the background.

Brands using this color

Fonts for this mood

#03599b reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #03599b
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 #03599b and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/03599b-9caec4-df4e56-1f212d-e9f1f1?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