The present disclosure provides a backlight, a backlight module and a display apparatus. The backlight includes a backplane, a reflective sheet and a plurality of light-emitting elements, the reflective sheet is arranged on an inner surface of the backplane, the backlight also includes at least one light-modifying region, the light-modifying region is arranged on the reflective sheet, the light-modifying region comprises at least one light-converting device, and the light-converting device can carry out optical process on light emitted from the light-emitting elements.