I have this problem that sometimes i need various polymer clay colors,but i can't afford them all! So i came up with this great solution.
To start,gather your light colored polymer clay and pastel crayons.For this tutorial,i used oil pastels.
Oil pastels are more oily than simple pastels.You can buy them in most craft stores.
Pastels are more dry than oil pastels.When i went to Art school,we were drawing with these on special surfaces. I think you can buy them in art stores. But you can also use pastels to make fimo cakes or other stuff to make them look more realistic.
To start making your own colored clay,gather some light colored clay and crayon of your choice.
Scratch some crayon onto polymer clay and mix in.
This how your clay will look after the crayon is added.
Make us much colors as you like!