Color

#3d0099

#3d0099
hex#3d0099
rgbrgb(61, 0, 153)
hslhsl(264, 100%, 30%)
oklchoklch(0.347 0.2 287)
Closest name: Galactic Civilization (#442288)Relative luminance 0.0329

Colors that go with #3d0099

Cobalt Blue, Royal Blue 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 →

#5c9900

#000f99 · #8a0099

#993d00 · #00993d

Split-complementary

Open in tool →

#998a00 · #0f9900

#99000f · #5c9900 · #00998a

Contrast

#3d0099 as textRatioAAAA largeAAAFix
Aaon white
12.66:1passpasspassPasses AAA — no fix needed.
Aaon black
1.66:1failfailfail
  • AA: use #9147ff as the text (4.55:1)
  • AAA: use #af7aff as the text (7.05:1)
  • AA: or shift the background to #9c9c9c (4.61:1)
  • AAA: or shift the background to #c2c2c2 (7.11:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3d0099 as the background.

Brands using this color

Fonts for this mood

#3d0099 reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3d0099
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 #3d0099 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3d0099-b19cc4-dfd34e-2b1f2d-e9eaf1?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