Color

#278b5e

#278b5e
hex#278b5e
rgbrgb(39, 139, 94)
hslhsl(153, 56%, 35%)
oklchoklch(0.568 0.115 159.3)
Closest name: seagreen (#2e8b57)Relative luminance 0.197

Colors that go with #278b5e

Charcoal, Crimson and Medium Violet Red 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 →

#8b2754

#278b2c · #27868b

#5e278b · #8b5e27

Split-complementary

Open in tool →

#8b2786 · #8b2c27

#2c278b · #8b2754 · #868b27

Contrast

#278b5e as textRatioAAAA largeAAAFix
Aaon white
4.25:1failpassfail
  • AA: use #258359 as the text (4.7:1)
  • AAA: use #1c6343 as the text (7.2:1)
  • AA: or shift the background to #0f0f0f (4.51:1)
Aaon black
4.94:1passpassfail
  • AAA: use #30ab74 as the text (7.2:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #278b5e as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

mcpConnect your agent — build around #278b5e
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 #278b5e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/278b5e-a2beb5-d459cc-1f2d2d-e9f1ea?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