There are two main types of scratches that occur in Metallic, Non-Metallic & Tri-Colour paint. Learn about Metallic Paint. The first type of scratches is light brushed scratches. These types of scratches are light and whitish looking and only need clear to camouflage. The other type of scratch is deep & discoloured where either metal or plastic surface is visible and will require primers so this type of scratch does not need clear at this point of the repair so GO straight to colour.
Stage 1: Your car is painted in layers from the factory so when your paint is scratched there are different levels of damage that occur in a single impact. Stage 1) light scratches where only the clear is damaged and needs the first 3 steps of this metallic repair manual to either completely remove the scratch or camouflage it so it is barely noticeable.
Stage 2) Where primers, colour & clears layers that are completely removed and either bare metal or bare plastic is exposed & the appropriate paint layer needs to be applied in the same way the factory formula is sprayed. So Basically fix the light scratches first using stage 1 & then using stage 1 & stage 2 together to repair, remove & camouflage heavier paint chips, scratches & blemishes.