A projection system includes a light source system that has a first light source for emitting first light, and a rotating color wheel that has at least a first fluorescent color band to absorb the first light and generate second light, and a second fluorescent color band to absorb the first light and generate compensation light. A light splitting device sequentially splits the first and second lights into light travelling along first and second light paths respectively. A first light modulation device modulates the light travelling along the first light path, and a second light modulation device for modulating the light travelling along the second light path. The first light is a primary light, the second light is a wide-spectrum light comprising at least two kinds of primary light, and a combined light of the first light and the second light comprises light of three primary colors.