Rewriteable Color Images (IMAGE) Rice University Caption These structural colors were printed on the same sheet of paper coated with copolymers through the application of ammonium persulfate and ethanol. Hydrogen bromide was used to neutralize the solvents and create a blank paper on which to print again. Credit Rice University Usage Restrictions For news reporting purposes only. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.