How many standard and non-standard Great Dane colors are there?

Answer 1

There are six standard "show" colors in the U.S.; Fawn, brindle, black, blue, mantle, and harlequin.

If you include non standard colors there are at least 29 total color/marking combinations I can recall; piebald/plattenhund, merle, blue merle, red merle, blue mantle, fawn mantle, brindle mantle, fawn harlequin, brindle harlequin,

blue harlequin (or porcelain), merle harlequin, blue merle harlequin, red merle harlequin, chocolate, chocolate mantle, chocolate merle, chocolate harlequin, blue masked fawn, chocolate masked fawn, merle masked fawn, blue brindle, blue brindle harlequin, and white.

I'm not sure on different colors of piebalds, haven't seen one, but I imagine each color category is possible.