The true statement about white light is:
White light is made up of a spectrum of many different colors.
White light is actually a mixture of various colors, which can be observed when light passes through a prism and is dispersed into a spectrum, showing colors like red, orange, yellow, green, blue, indigo, and violet. The other statements are incorrect. White light is not made up of only one color, it does not mainly consist of ultraviolet and infrared light, and it does not fall within the microwave portion of the electromagnetic spectrum.