Oxymoron
The combination of contradictions is called an oxymoron. Silent scream, deafening silence, dark day, pretty ugly, darkness visible etc. are some oxymora. (correct plural of oxymoron; not oxymorons)
Objective oxymoron
Those oxymora that use apparent contradictions like angry saint or bitter sweet are called objective oxymora. They are quite literal, without any hidden meanings.
