I recently finished my basement. Had the drywall textured. Painted three sample areas of different paint colors I was trying to decide on. I decided on one and got the paint from a different paint store than the samples. I primed over the samples with two coats and then painted three coats of paint on the walls. When dried I could see the areas that I painted the samples were shinier than the rest of the wall. Any one know why this is or how to fix it. Thanks!
Did you just apply primer over the paint sample areas? If so, the primer left the wall in that area with a different surface preparation than the rest of the area where you applied the top coats. The different sheen that you see is probably mostly due to how light reflects off the wall in that area.
One fix that may be possible, particularly if you had painted with a egg shell or low luster type paint, is to repaint with a flat paint.
I'm assuming you also primed the rest of the walls too & not just the patches. The Sheen should even up in a month. Like, I had trouble with Sherwin William's primer & paint revealing patches primed with a standalone primer, but it finally leveled off.
Otherwise, you might need to very lightly "sand" or scrub the areas with a kitchen scrubby or even triple-zero steel wool (an S.O.S. pad will work) to buff-down that sheen. But definitely, just wait first to see if it's just a curing difference.