Question

How do white colour reflects radiation?

Answer 1

It is not exactly a case of reflecting or absorbing "heat". An object appears white if it reflects light. If an object absorbs light, the energy of the light is converted into heat energy within the object. Therefore, a white object will absorb less radiation and therefore will heat up less when exposed to light. Note that a this only applies for heat transfer via radiation. The colour will have no effect on the amount of heat transferred by direct conduction.