Abstract: A tire pressure cover utilizing colors to indicate tire pressure includes mainly a transparent cover and a metal housing. The metal housing houses an alarm bolt, a spring, a floating seat, a rubber pad, an air ventilating plate, and a gasket. When the tire pressure cover is locked to the air nozzle of a tire, the air inside the tire will enter the tire pressure cover and pass through the air ventilating plate to push the rubber pad, which in turn forces the floating seat thereon to rise so that the spring disposed in the floating seat is compressed. The floating seat will become stationary when the internal and external pressure of the tire pressure cover and the tire are balanced. The alarm bolt has a red section and a yellow section. When the floating seat elevates, it may conceal the alarm bolt completely or in part. The user may, by looking at the color exposed on the alarm bolt to determine whether the tire pressure is sufficient.