On Color:
the green of a photographed field, for example, is an image of CONCEPT ‚green‘, just as it occurs in chemical theory, and the camera (or rather the film inserted into it) is programmed (or trained) TO TRANSLATE this concept into the image

the more genuine the colors of the photograph become, the more untruthful they are, the more they conceal their theoretical origin
Thus colour photographs are on a higher level of abstraction than black-and-white one
Black-and-white one are more concrete and in this sense more true: they reveal their theoretical origin more clearly and vice versa