Here’s a quick tip about painting with red paint; you need to use a tinted primer first!
Nine times out of ten; when painting (anything) with red paint, you will need to use a tinted primer first; preferably gray. The only exception I can think of where a primer is generally not needed when painting with red is when using red nail polish. Go figure ?
What happens if you don’t prime first? Your paint will probably look translucent, somewhat like this: 
What I mean is that you will see through each coat of paint, layer after layer & so on. You will continue to see brush strokes and roller marks even after applying multiple coats of paint.
(walls before primer)
I used “Zinsser Bulls Eye 1-2-3 Primer and Sealer” pre-mixed in Gray from
Home Depot. You can find it here:
The Home Depot
(walls after gray primer)
(walls after primer and red paint)
We use a lot of products from “Zinsser” because they work great for their individual intended purpose and are not expensive. This primer was particularly useful because it came pre-mixed, it’s water-based and is suitable for both interior and exterior projects.
Just remember to ask for the can to be shaken before buying!