A hypomelanistic (or ghost) animal has a "reduced" (aka hypo) amount of melanin pigment, they have a reduced amount of black coloring giving them a faded, lighter appearance .... like this animal ...



A hypermelanisitic animal has an increaded (aka hyper) amount of melanin pigment, they have an extreme amount of black coloring giving them a dark, sooty appearance ... like this animal ....



Hope this helps.

-adam