Color

#3900a3

#3900a3
hex#3900a3
rgbrgb(57, 0, 163)
hslhsl(261, 100%, 32%)
oklchoklch(0.355 0.211 282.8)
Closest name: Galactic Highway (#3311bb)Relative luminance 0.0351

Tints & shades

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

Harmonies

Complementary

Open in tool →

#6aa300

#0018a3 · #8b00a3

#a33900 · #00a339

Split-complementary

Open in tool →

#a38b00 · #18a300

#a30018 · #6aa300 · #00a38b

Contrast

#3900a3 as textRatioAAAA largeAAAFix
Aaon white
12.33:1passpasspassPasses AAA — no fix needed.
Aaon black
1.7:1failfailfail
  • AA: use #8b4dff as the text (4.6:1)
  • AAA: use #ac80ff as the text (7.29:1)
  • AA: or shift the background to #9e9e9e (4.6:1)
  • AAA: or shift the background to #c4c4c4 (7.07:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3900a3 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

#3900a3 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3900a3
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — generate_palette, check_contrast, analyze_color — read-only, no key. Every palette it proposes comes with a /palettes/new/… link: open it, lock what you like, paste the link back.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #3900a3 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3900a3-af9cc4-dfcb4e-2a1f2d-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