ANTITA,,,,,,,,,you are spot on , marc de champagne and grappa are pretty much the same thing , both fermented from the
second pressing of grape skins,,,,,, a touch "rough" on the palate but absolutely ideal for rind washing
it doesn't matter if red or white grape skins are pressed as the fermented liquid under pot distillation and / or column
rectification will render the yield colourless,,,,,i spent some 47 years on and off up around your way , mostly asleep in beverage
labs,,,,,,,,,,good luck , many regards ,brian