Sylvester (tuxedo or black with white)
Sylvester jr., Sylvester's son (tuxedo or black with white)
Alan, Sylvester's brother (auburn shade of orange)
Sylvester and Alan's mom (orange with white)
Silvia, Sylvester's wife (light yellow shade of cream with white)
Mrs. Sylvester, Sylvester's wife and Sylvester jr.'s mom (grey with white)

If Sylvester's family tree followed the rules of real life cat coat color genetics, Sylvester and Alan's mom would have to be a cryptic tortie who looks basically orange. Cryptic torties and torbies (tortoiseshell tabbies), which occasionally show up, are genetically tortoiseshell cats that look nearly or completely orange based color (like red/orange/ginger and cream/buff) or black based color (like black, grey/blue, chocolate, lilac, cinnamon, and fawn). Sylvester and Alan's unknown father or fathers can either be black or orange.

Note: "With white" means with low grade white spotting (like locketed, mitted, or tuxedo). "And white" means with medium grade (like bicolor or mask-and-mantle) or high grade white spotting (like cap-and-saddle, harlequin, or van pattern). Tuxedo cats are black cats with white feet, bellies, and chests. White tail tips and facial markings like a white muzzle, chin, or blaze are optional.

Sylvester, Sylvester jr., Sylvia, Alan, Sylvester and Alan's mom, Mrs. Sylvester, Looney Tunes, and The Looney Tunes Show: (c) Warner Bros.