Primer Sealer and Red Oxide question

I'm getting close to the stage of laying base on the car (GA4) and have a couple of questions. Currently, the car is in PPG Urethane high build and is going to be block/wet sanded to around 700 grit, I have been debating if I should use a sealer over this or just skip the hassle and spray base directly on the high build. The second question is how much does the color of what the base is sprayed onto effect its shade and look on the finished product, seeing as the factory used a Red Oxide primer for GA4 how much did it affect the finished color and if I do use a sealer should I get it tinted like it? This is going to be my first time painting a car and would like some feedback on this, it would be a big help.


This is the Color of the car
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