I need to turn off a setting that I can't find

Hi.  I'm new Corel and have very little time to do the tutorials to find the answer to this question.  I'm making a bulletin board and each time I go to add color to a box I'm working with it comes out white or light-colored (faded) beginning on the left and then brightens and becomes nearly solid on the other side.  I know it's got to be a setting that has somehow been selected that I don't want to use, but for the life of me, I can't find it to turn it off.  Please help.