Color

#343d51

#343d51
hex#343d51
rgbrgb(52, 61, 81)
hslhsl(221, 22%, 26%)
oklchoklch(0.36 0.037 265.8)
Closest name: Charcoal (#36454f)Relative luminance 0.0466

Colors that go with #343d51

Dark Olive Green, Sea Green and Steel 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 →

#514834

#344c51 · #393451

#51343d · #3d5134

Split-complementary

Open in tool →

#513934 · #4c5134

#51344c · #514834 · #345139

Contrast

#343d51 as textRatioAAAA largeAAAFix
Aaon white
10.87:1passpasspassPasses AAA — no fix needed.
Aaon black
1.93:1failfailfail
  • AA: use #63759c as the text (4.56:1)
  • AAA: use #8996b3 as the text (7.08:1)
  • AA: or shift the background to #a8a8a8 (4.57:1)
  • AAA: or shift the background to #d1d1d1 (7.12:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #343d51 as the background.

Brands using this color

Fonts for this mood

#343d51 reads as cool, muted, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #343d51
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 #343d51 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/343d51-9ca4c4-df6b4e-211f2d-e9eff1?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