I am painting my bedroom and was painting white matt emulsion over cream matt emulsion. Last week I painted one coat, and this week decided to paint a second. When I was painting under the window I noticed bubbling on the original first coat it had cracked so I removed the loose paint which went down to the plaster. Another patch came off on the roller again going own to the plaster. I thought by removing loose bubbling paint and sanding the edges and repainting all would be ok. Now I have 2 patches that are much whiter on the patches and stand out terribly from the rest of the wall. What can I do now??? I want it to blend in!!!