Color

#403c8b

#403c8b
hex#403c8b
rgbrgb(64, 60, 139)
hslhsl(243, 40%, 39%)
oklchoklch(0.406 0.127 281.4)
Closest name: darkslateblue (#483d8b)Relative luminance 0.0619

Colors that go with #403c8b

Charcoal, Steel Blue and 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 →

#878b3c

#3c5f8b · #673c8b

#8b403c · #3c8b40

Split-complementary

Open in tool →

#8b673c · #5f8b3c

#8b3c5f · #878b3c · #3c8b67

Contrast

#403c8b as textRatioAAAA largeAAAFix
Aaon white
9.39:1passpasspassPasses AAA — no fix needed.
Aaon black
2.24:1failfailfail
  • AA: use #716dc0 as the text (4.65:1)
  • AAA: use #9390d0 as the text (7.14:1)
  • AA: or shift the background to #b5b5b5 (4.58:1)
  • AAA: or shift the background to #e0e0e0 (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 #403c8b 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

#403c8b reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #403c8b
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 #403c8b and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/403c8b-a39cc4-dfa04e-261f2d-e9edf1?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