Color

#003a66

#003a66
hex#003a66
rgbrgb(0, 58, 102)
hslhsl(206, 100%, 20%)
oklchoklch(0.341 0.094 248.8)
Closest name: Atlantic Navy (#13336f)Relative luminance 0.0399

Colors that go with #003a66

Crimson, Royal Blue and Teal 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 →

#662c00

#00665f · #000766

#66003a · #3a6600

Split-complementary

Open in tool →

#660007 · #665f00

#5f0066 · #662c00 · #076600

Contrast

#003a66 as textRatioAAAA largeAAAFix
Aaon white
11.69:1passpasspassPasses AAA — no fix needed.
Aaon black
1.8:1failfailfail
  • AA: use #0076d1 as the text (4.51:1)
  • AAA: use #1499ff as the text (7.03:1)
  • AA: or shift the background to #a1a1a1 (4.52:1)
  • AAA: or shift the background to #c9c9c9 (7.06:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #003a66 as the background.

Brands using this color

Fonts for this mood

#003a66 reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #003a66
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 #003a66 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/003a66-9caec4-df4e56-1f212d-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