Color Problem Around Switch
As you can see in the picture above the arrows
are pointing to what seems to be a different paint color. The arrows are
pointing to the top and bottom of what seems to be some sort of repair
job around these light switches.
Now keep in mind the two different colors does not mean there has been a repair job. Someone could have simply went down and bought some touch up paint and applied it to the wall to make the home look nicer for resale.
It wouldn't be a bad idea to take the covers off and check for new electrical boxes or signs of any sort of repairs and and even if there were no repairs this would give you a good chance to look at the house electrical wiring.
It wouldn't be a bad idea to look on the other side of the wall if possible to see you have there is any signs of wall patching.