White roof paint greatly reduces the amount of heat a building absorbs from the sun, which significantly cuts the cost of heating and cooling a structure, experts say. In California, the Anaheim Hilton is covered with a topcoat of paint that is filled with tiny hollow glass balls that deflect heat. The roof cost $150,000 to install, far less than it would have cost for a traditional repair. Hilton believes energy savings will be so significant that it might add similar roofs to all of its hotels. Meanwhile, the Department of Energy is urging consumers to invest in cool roofs, and large companies have started to develop eco-friendly roof paints.