Often it’s not the colour that shows through, it’s the texture, which would take quite a few coats to blend in. There are thicker primers made to even out texture differences though so a tinted coat of that and one coat of paint would probably do it.
It can be but to be honest - and having painted over a wall painted with differing paint before - the ultimate difference is not noticeable unless you’re looking for it.
Often it’s not the colour that shows through, it’s the texture, which would take quite a few coats to blend in. There are thicker primers made to even out texture differences though so a tinted coat of that and one coat of paint would probably do it.
It can be but to be honest - and having painted over a wall painted with differing paint before - the ultimate difference is not noticeable unless you’re looking for it.