Color

#00378f

#00378f
hex#00378f
rgbrgb(0, 55, 143)
hslhsl(217, 100%, 28%)
oklchoklch(0.369 0.155 260.5)
Closest name: Deep Space Royal (#223382)Relative luminance 0.0472

Tints & shades

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

Harmonies

Complementary

Open in tool →

#8f5800

#007e8f · #11008f

#8f0037 · #378f00

Split-complementary

Open in tool →

#8f1100 · #7e8f00

#8f007e · #8f5800 · #008f11

Contrast

#00378f as textRatioAAAA largeAAAFix
Aaon white
10.81:1passpasspassPasses AAA — no fix needed.
Aaon black
1.94:1failfailfail
  • AA: use #0f6bff as the text (4.57:1)
  • AAA: use #5294ff as the text (7.04:1)
  • AA: or shift the background to #a8a8a8 (4.55:1)
  • AAA: or shift the background to #d1d1d1 (7.08:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #00378f as the background.

Brands using this color

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

Palettes built around it

Fonts for this mood

#00378f reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #00378f
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 #00378f and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/00378f-9ca7c4-df624e-201f2d-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