Well... not really vice versa. Because FE8 do have more sharper design.
However if I use an FE8 style... ie: 7 4 8 (iirc) or darker shade. Will it affect the game? Or is it just for purely aesthetic.
I am dabbling with a FE7 hack (and 8) ... however... I realized that most (if not all) FE7 hacks.. uses FE7 lighter tone shading... when FE8 is available.
EDIT: Does it hurt if a hack have some FE7 map follows my FE8? I know consistency isnt there... but helps a hacker progress... then he can fix it after.