Cleaning any leather depends on what the finish is. All cars with OEM leather seats are finished with a very tough PU finish which is reasonably abraision resistant and resistant to wet rubbing, so for this type of leather, whatever the colour , cleaning with a mild detergent solution is the best option. Oils or waxes may soften the finish and make it susepable to cracking and splitting causing premature ware. Modern Fully pigmented domestic upholstery, is likely to be of a similar finish , but generally the performance of the finish is not required to be so good,therfore the cleaning method used should be the same as for Auto upholstery, although more care should be taken. Different rules apply to semi aniline finished upholstery leathers or the Chesterfield type finishes. These will be much more likly to come off with any sort of cleaning. (The Chesterfield finish is a traditional rub off finish, designed to come off with time.)