Never used it but if it includes the primer I assume it is the correct color/shade for the base color.
You can have a perfect match yet without the exact shade/color primer have a total mismatch. This is the reason for doing a spray out before shooting on the panel.
I use these before spraying the panel, paint the little car same as you will the panel, record psi and primer shade and number of coats, shoot the same when it matches perfectly. A little extra works but its spot on every time when you take a gun to the car, it makes blending a breeze.