Which color pattern is not acceptable for Cavalier King Charles Spaniels?

The color pattern that is not acceptable for Cavalier King Charles Spaniels is solid black.

The Cavalier King Charles Spaniel breed standard recognizes four acceptable color patterns:

* Blenheim: White with rich mahogany markings.

* Tricolor: White with black and tan markings.

* Ruby: Rich, solid red.

* Black and Tan: Black with tan markings.

Solid black is not recognized as a valid color pattern for the breed.