They may be night sights. Before painting over them, check them out in the dark. If they are bright night sights you may want to leave them as is. If they are night sights that have lost their glow, then paint over them like the others have said.
I had a 5906 and the dots fell out of the rear sight. I cleaned and degreased the holes, then put in a new dot with a little white Testors model paint on the end of a toothpick. Let it dry for a day and I had new bright white dots.
I just happened to have a little jar of the Testors paint, but any white acrylic or enamel will work. Just make sure there's no oil or crud in the holes.
I have used the correction fluid before, but found it a bit 'soft' and it wore off easy. Then I wised up and stole nail polish from my daughters. It works great ...... until they saw the bottles one day and repossessed.