Color

#304dab

#304dab
hex#304dab
rgbrgb(48, 77, 171)
hslhsl(226, 56%, 43%)
oklchoklch(0.454 0.155 267.1)
Closest name: Blasphemous Blue (#3356aa)Relative luminance 0.0888

Colors that go with #304dab

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.

Tints & shades

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

Harmonies

Complementary

Open in tool →

#ab8e30

#308aab · #5130ab

#ab304d · #4dab30

Split-complementary

Open in tool →

#ab5130 · #8aab30

#ab308a · #ab8e30 · #30ab51

Contrast

#304dab as textRatioAAAA largeAAAFix
Aaon white
7.57:1passpasspassPasses AAA — no fix needed.
Aaon black
2.78:1failfailfail
  • AA: use #5471cf as the text (4.64:1)
  • AAA: use #8095db as the text (7.24:1)
  • AA: or shift the background to #c9c9c9 (4.57:1)
  • AAA: or shift the background to #f7f7f7 (7.06:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #304dab as the background.

Brands using this color

Fonts for this mood

#304dab reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #304dab
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 #304dab and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/304dab-9ca1c4-df774e-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