[Daub]

Not exactly made up. Having only the lightness values to start with, The task is to define the hue and saturation. Though in theory there is no way to know for certain what they originally were, in practice certain lightness values are associated with some hues more than others. Also, saturation values tend to follow lightness values quite closely. Add to that the fact that Klimt (like most painters) employed a habitual pallet, you are half was to a good guess.