This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC’s registered office is 5 Howick Place, London SW1P 1WG. How Did NASA Take a Photo of a Black Hole? Which Motors Are the Best: Servos or Steppers? Color-changing materials could be used in camouflage, skyscraper windows, and even in cosmetics and clothing.