Right, sorry for the delay in response, i try to follow as many threads in as many forums as possible but will inevitably miss some. but now i have seen it (thanks Mike) i will give you my best shot at an answer:
in the Core Eight there are 4 soft and 4 hard waxes. the difference in these waxes is simply the firmness of the waxes themselves. the main reason for creating a set of each is to cater for the different application methods; by finger/palm or by foam applicator. the finish of the like for like soft to hard wax will be much the same on the paint.
what i would say is that it is more difficult to apply a thin and consistant layer by finger/palm without practice, in comparison to by foam applicator. that is why we have always advised to put a hard wax on before a soft wax if both should be used. it is always recommended to put 2 layers on with at least an hour or two of curing between in order to get best coverage. with two layers on the car you will get 2-3 months of durability with a good maintenance regime.
as for the colour of your cars, it is important to know that any of our waxes can be put on any colour car. although specifically, Rainforest Rub (soft) and Hard Candy (hard) are made to suit any colours, the other colour charged waxes will not 'change the colour of your car once buffed'. however, there are slight differences in the colour of the ingredients and subtle formulaic changes which will subjectively enhance the colours they are developed for.
so for a dark car, if you wanted to go with finger/palm application i would go for Purple Haze or Blue Velvet, if you prefer to use a foam applicator. you can use the same waxes on the white car, will get good results but will not have quite the same gloss and shine as with Light Fantastic or Diamond White.
hope this makes sense. 8)
