We learn at an early age that black absorbs the heat from the sun, while white reflects it. It usually just takes one afternoon wearing a dark shirt while playing outdoors to teach us about heat absorption.
Your commercial roof is the same. In fact, we have a name for it: the “Heat Island Effect.” That term refers to the heat that is absorbed from the sun’s ultraviolet radiation and transferred to the building interior. During much of the year this increases the demand for power as air conditioning systems labor to maintain a comfortable working environment.