A display apparatus comprises a light source device, an image data processing module, a light modulating device and an image synthesizing device. The light source device is configured to emit first light and second light. The image data processing module is configured to receive original image data of an image to be displayed, wherein the original image data of the image to be displayed is based on image data within a second color gamut range and comprises original control signal values of m colors of each pixel; the second color gamut range covers a first color gamut range and has a portion that exceeds the first color gamut range. The image data processing module is further configured to map the original control signal values of the m colors into m corrected control signal values corresponding to the first light and n corrected control signal values corresponding to the second light.