break sugar cookie dough in half, break one half into equal sized balls (as many as you have colors)

mix a couple drops of food dye into each ball

break other half of cookie dough into like sized balls

roll each ball out and stack on top of each other alternating the undyed pieces with the colored ones

fold in half and mix a little bit. BE CAREFUL NOT TO OVER MIX OR YOU WILL END UP WITH A SOLID COLOR

if making cut out cookies start with the dough colors barely mixed because each time you have to re roll the dough the colors will mix more