There is no color information when you are converting photons to electrons, right?
Depends on what you mean by "convert." Photons have subjective color information from their capture scenario. Whether that information gets converted into the resulting electron stream data is up to the conversion process.
Let's keep it simple. The typical photodetector will release an electron whenever a photon of sufficient energy (>= "work function") bangs into it, knocking out an electron. The energy of the photon is directly proportional to its frequency = color. Therefore, to discriminate color with these type of detectors you put an optical color filter in front of each pixel that passes either Red, Green, or Blue. By knowing which detector pixel had which filter color, you can recreate the original image in RGB, which is how the human eye works. So while the color LOOKS very good there is actually a tremendous loss of spectral information occurring.
Moreover, most color cameras use a filter made up of tiles of filters, each tile having a square sub-grid of 2 Green pixels, 1 Red pixel, and 1 Blue pixel. Soooooo - the color also comes at the expense of reducing image resolution by 4.