Hi everyone! I am doing an old school nintendo cake as we speak. The system is two different shades of gray, dark on the bottom and light on the top. I was going to use buttercream but since I need to use fondant for the controllers and want the colors to match exactly, I figured I should just cover the cake in fondant too. My question is, how to I achieve this two tone look? I don't have too much experience covering cakes in fondant. Do I cover the entire cake the bottom shade first, and then roll out enough fondant to cover the top half in the lighter color? If so, how do I do that so that the point where the two colors meet is a straight line? Any help is truly appreciated!!!

You've got it..
Cover the entire cake in fondant - then for the top shade of the controller - put your fondant on that part. I usually achieve this with eye measurements - you can always measure exactly the size you want so you won't have to keep on trying to get it right!
Good luck!

You could also cover the whole thing in light grey, and then make a dark grey band to wrap around the bottom. Or you could just cover the whole thing in the light grey, and paint the bottom the darker colour.