Any part that has a stud on the surface can be fairly easily removed by using leverage from a different large part added to the top of it. This takes advantage of the inherent "clutch power" of the stud/anti-stud connection and the increased surface area of the larger part to concentrate the force used to remove the part in a lateral direction.
For example, by placing a 1x6 plate over the trans-yellow 1x1 plate and then pushing the 1x6 plate away from the trans-orange plate will likely pull the trans-yellow plate up fairly easily.
LEGO also produces a purpose built tool called the Brick Separator that uses both that technique as well as giving additional leverage by pushing the part with the under or over-hanging ledge on the top and bottom of the front of the tool.