How primer affect body color?

I painted X7 red over Testor's white primer
and got unpleasant tint of pink and blue on the edges
where the paint layed thin
Also this primer CRACKS on cold!

Perhaps more than one coat is in order?

How long before you painted the top finish coat?
You need to leave it for 7-10 days at least before painting a top coat.
Sounds like they may not get on to well together.

I'd ditch the Testors and get the Tamiya primmer.

I'm waiting already two weeks for Tamiya primer
it's hard to find in my area

Then go for automotive plastic primer or bumper primer!