Color

#3917a1

#3917a1
hex#3917a1
rgbrgb(57, 23, 161)
hslhsl(255, 75%, 36%)
oklchoklch(0.367 0.198 281.9)
Closest name: Depths of Night (#2c319b)Relative luminance 0.0406

Colors that go with #3917a1

Denim, Blue and Crimson 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 →

#7ea117

#1739a1 · #7e17a1

#a13917 · #17a139

Split-complementary

Open in tool →

#a17e17 · #39a117

#a11739 · #7ea117 · #17a17e

Contrast

#3917a1 as textRatioAAAA largeAAAFix
Aaon white
11.59:1passpasspassPasses AAA — no fix needed.
Aaon black
1.81:1failfailfail
  • AA: use #815ee8 as the text (4.7:1)
  • AAA: use #a087ee as the text (7.19:1)
  • AA: or shift the background to #a3a3a3 (4.6:1)
  • AAA: or shift the background to #c9c9c9 (7:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3917a1 as the background.

Brands using this color

Fonts for this mood

#3917a1 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3917a1
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 #3917a1 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3917a1-ab9cc4-dfbd4e-291f2d-e9ebf1?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