Cardigan Welsh Corgis have a wider range of colours and patterns than the Pembroke Corgis do.
Depending upon the country there are different colours that are acceptable. The country of origin standard (U.K.) and the Canadian standard both say “Any colour, with or without white markings, but white should not predominate”
The standard for the U.S.A. list the only colours acceptable as Red, Sable, Brindle, Black and White with Tan or Brindle points, and Blue Merle with Tan or Brindle points.
For further information on acceptable colours in the Cardigan Welsh Corgi see the following links:
Cardigan Welsh Corgi Club of America – Genetic information on Colors
Cardigan Commentary International – Cardigan Welsh Corgi Colors