The specification and drawings present a new method, apparatus and software product for dynamically adjusting a color gamut of a display (e.g., a field sequential color display) and further adjusting a luminance of the display in an electronic device by adjusting and turning on field duties of primary colors. During each color field, the other primary colors of light sources supporting the display can be turned on at their respective fractions of their color field. These fractions can be continuously tunable in order to control the color coordinate of each primary color dynamically thus adjusting the color gamut and the luminance of the display.