Color

#303ebb

#303ebb
hex#303ebb
rgbrgb(48, 62, 187)
hslhsl(234, 59%, 46%)
oklchoklch(0.44 0.194 270.8)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0766

Colors that go with #303ebb

Charcoal, 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 →

#bbad30

#3083bb · #6730bb

#bb303e · #3ebb30

Split-complementary

Open in tool →

#bb6730 · #83bb30

#bb3083 · #bbad30 · #30bb67

Contrast

#303ebb as textRatioAAAA largeAAAFix
Aaon white
8.29:1passpasspassPasses AAA — no fix needed.
Aaon black
2.53:1failfailfail
  • AA: use #616dd6 as the text (4.67:1)
  • AAA: use #8992e1 as the text (7.26:1)
  • AA: or shift the background to #bfbfbf (4.51:1)
  • AAA: or shift the background to #ededed (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 #303ebb as the background.

Brands using this color

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

Fonts for this mood

#303ebb reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #303ebb
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 #303ebb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/303ebb-9d9cc4-df8a4e-241f2d-e9eef1?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