Color

#337fd1

#337fd1
hex#337fd1
rgbrgb(51, 127, 209)
hslhsl(211, 63%, 51%)
oklchoklch(0.59 0.146 253)
Closest name: Haddock’s Sweater (#277aba)Relative luminance 0.2049

Tints & shades

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

Harmonies

Complementary

Open in tool →

#d18533

#33ced1 · #3633d1

#d1337f · #7fd133

Split-complementary

Open in tool →

#d13633 · #ced133

#d133ce · #d18533 · #33d136

Contrast

#337fd1 as textRatioAAAA largeAAAFix
Aaon white
4.12:1failpassfail
  • AA: use #2d78c8 as the text (4.53:1)
  • AAA: use #225a96 as the text (7.07:1)
  • AA: or shift the background to #121212 (4.55:1)
Aaon black
5.1:1passpassfail
  • AAA: use #5d99da as the text (7.03:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #337fd1 as the background.

Brands using this color

Fonts for this mood

#337fd1 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #337fd1
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 #337fd1 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/337fd1-9cabc4-df534e-1f202d-e9f1f1?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