Ambient light sensing and proximity sensing is accomplished using pairs of stacked photodiodes. Each pair includes a shallow diode with a shallow junction depth that is more sensitive to light having a shorter wavelength and a deeper diode with a deeper junction depth more sensitive to light with longer wavelengths. Photodiodes receiving light passed through cyan, yellow, and magenta filters and light passed without a color filter are used to generate red, green, and blue information through a subtractive approach. The shallow diodes are used to generate lux values for ambient light and the deeper diodes are used for proximity sensing. One or more of the deep diodes may be used in correction to lux determinations of ambient light.