Color

#303d91

#303d91
hex#303d91
rgbrgb(48, 61, 145)
hslhsl(232, 50%, 38%)
oklchoklch(0.401 0.138 272)
Closest name: Bluebell (#333399)Relative luminance 0.0601

Colors that go with #303d91

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 →

#918430

#306e91 · #543091

#91303d · #3d9130

Split-complementary

Open in tool →

#915430 · #6e9130

#91306e · #918430 · #309154

Contrast

#303d91 as textRatioAAAA largeAAAFix
Aaon white
9.54:1passpasspassPasses AAA — no fix needed.
Aaon black
2.2:1failfailfail
  • AA: use #5e6dc9 as the text (4.51:1)
  • AAA: use #8893d7 as the text (7.2:1)
  • AA: or shift the background to #b3b3b3 (4.55:1)
  • AAA: or shift the background to #dedede (7.09:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #303d91 as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#303d91 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #303d91
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 #303d91 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/303d91-9c9dc4-df864e-231f2d-e9eef1?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