Bit late but if you still want green bedding in the future:
How to Make Hamster Bedding Similar to Carefresh: 6 Steps
I've done this and I'd reccomend using toilet paper instead, plain paper came out a little hard, but that may have been the baking soda I added (you can add some for absorbancy, I may have used too much :P) or just the type of paper. But you can add food colouring to it
Just be sure to lay it out in one layer and if possible leave it by a heater or out in the sun to dry.