Choose your base coat color (ie: silver, blue, white, etc.)
Pearls and kandy's are topcoats
Decide what effect you want out of the paint. (stock= base+clear)
There are many kandy and pearl colors available. Kandy is going to give you a really rich paint look to the base coat, bringing out the vibrant colors of the base coat.
Pearls are going to give you a different effect depending on light conditions. I don't think pearls are as vibrant as kandy top coats.
since the silver isn't a very vibrant color like reds or blues, a pearl would look best.
Pearls:
Base coat (color?) + Top coat (pearl color?) + Clear coat
Kandy:
Same as pearl except the top coat is the Kandy. Base+kandy top coat+clear coat.