A display apparatus comprising a light source device, an image data processing module, a light modulation 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, the original image data of the image to be displayed being image data based on a second color gamut range and comprising original control signal values of m colors of pixels, and the second color gamut range covers a first color gamut range and has a portion beyond the first color gamut range. The image data processing module further maps the original control signal values as m corrected control signal values and n control signal values.