This isn’t a major item in origami, until you get into more intricate designs. Many experienced origami artists use foil back paper for certain items that you aren’t going to be able to fold with regular paper. These items might include: antennae on insect designs, and possibly small legs on any of the other creatures that tickle your fancy.
You can usually find foil backed paper in a craft store and it can quite expensive. Some people make their own (quite inexpensively) but it can be messy, as it involves using craft glue and aluminum foil wrap along with tissue paper to give you the same kind of look.