Okay, let me start out by saying that I highly recommend getting a body kit installed by an auto body technician or someone who has done body work and feels comfortable completing the necessary work.
If you insist on installing the kit yourself, there are some things to consider.
What color are you going to paint your body kit?
Where are you going to paint?
How are you going to paint your body kit?
Do you have the right tools to install the kit yourself?
And are you going to paint your entire car or just the body kit?(Should you decide to get your car painted professionally, but not get the kit installed, skip the below steps.)
I personally recommend painting the kit the same color as your car, but that's personal opinion. Body kits can look really sharp if they are combined with vinyl graphics or even other custom paint work to tie the entire car together. I recommend finding your vehicles specific paint codes. Most of them can be found through the DuPont registry or through your local dealer.