This is a schematic chart of six different coat colors resp. patterns, which are confused frequently.
Four of them are called “harlequin”, but all of them have different genetic backgrounds. The three in the upper line base on a merle genotype, the three on the bottom line don´t. Note on the S-locus (see poodle, Dalmatian and Australian Cattle dog): The results can vary between differnt labs. I chose the abbreviations used by Laboklin: S for spotting and N for no spotting.