I have put primer over a black wall and want to paint it orange.
The problem is I put 4 coats of paint and it's not covering.I have
A thick expensive paint and don't understand.I was told to put
More coats until it's covered.Is this what I should do?

Pauline I have moved your question to a thread of its own so that it will get the answers it deserves, rather than riding on the coattails and getting mixed up with a totally different question. ;)

"biz" Is A Primer That Covers Water Stain And Other Things, You Make Want To Try It.

Accent base coat, bring your color back in two stages.
Ask your paint dealer for the base coat for the color you selected.