This is likely due to a rank-based post-color. Head to Admin > Security > Ranks, and make sure that the post color and background color for post is set to nothing, or at least let to an expected color. If you don't have access to that, have your site's super-admin check it out.
unfortunately, that did not fix my issue. I am beginning to think it is something messed up with the computer I use in general. When I make a post using a different computer, everything is fine. Just cannot figure out why on this specific computer it is white. I've updated video drivers and still no change