Automotive paint is not anything like house paint, or even industrial paint. I don't even recommend mixing of different brands. I recommend using only one manufacturer from start to finish. If you choose HOK, use their primers, colors, and clears for best results. These systems are designed to work together, mixing of different brands could cause problems. Maybe not immediately, but could cause delamination (peeling) problems after only a short time.
You can mix certain colors together to acheive a custom blend, get the tech sheets, these will tell you what you can and can't do with the product. It will also tell you about compatibility with other products. And how to mix and spray them properly.
Many people try to shortcut the material step, usually because of the cost. Remember the whole job is only as good as the first coat. What good is beautiful artwork if it won't stay stuck to the bike? or even if it has pimples, fisheyes, or blisters?
If you have never painted with automotive paints, I suggust going to your local jobber to see if there is a class you can take. All the major manufactures provide training classes at a nominal cost, usually a 2 day course, costing anywhere from free to a couple hundred bucks. These are great for the novice to learn some basic skills for refinishing. I have been painting over 30 years, and I still attend these classes regularly. They are an incredible source of information.
I recently attended the SEM school in Charlotte NC, total cost for me was 2 nights hotel and travel to and from Charlotte. ($225) SEM provided breakfast, lunch, and dinner, as well as transportation from the hotel to and from school, all materials, and even a nice t-shirt. I left there with a wealth of knowledge, I picked up a few new tricks from other painters who attended, as well as new techniques from the instructors. I now use more SEM products than HOK. Not because they are better, they are both exceptional products, but because I have a better understanding of how the SEM products work.
Good luck, and ask questions if you don't fully understand, it'll save you lots in the long run.