Well, to customize any Linux distro you need the controls and the light distros don't have them. If they were present I would find them but I havent so far and if a modern computer is needed your recommended distros will not help the OP.
I do have a modern computer, so shoot, show me where to find the controlls to customize Lubuntu 14.04 or 15.04, Semplice, ZorinOS, other light distros are the same as these last two so any advice for a light distro should work on any of these. I'd like to change the theme, folder icons and colors which is what the OP wants in the first place and didn't find in Lubuntu.