Color

#3979ef

#3979ef
hex#3979ef
rgbrgb(57, 121, 239)
hslhsl(219, 85%, 58%)
oklchoklch(0.599 0.19 261.3)
Closest name: Blue Öyster Cult (#5577ee)Relative luminance 0.2078

Tints & shades

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

Harmonies

Complementary

Open in tool →

#efaf39

#39d4ef · #5439ef

#ef3979 · #79ef39

Split-complementary

Open in tool →

#ef5439 · #d4ef39

#ef39d4 · #efaf39 · #39ef54

Contrast

#3979ef as textRatioAAAA largeAAAFix
Aaon white
4.07:1failpassfail
  • AA: use #2b6fee as the text (4.55:1)
  • AAA: use #1050c6 as the text (7.04:1)
  • AA: or shift the background to #141414 (4.52:1)
Aaon black
5.16:1passpassfail
  • AAA: use #6395f2 as the text (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 #3979ef 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

#3979ef reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3979ef
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 #3979ef and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3979ef-9ca5c4-df664e-211f2d-e9f0f1?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