General Studies · Logical Puzzle

Six boxes P, Q, R, S, T and U are painted with one among different colours Black, Blue, Orange, Green, White and Grey (not necessarily in the same order). No two boxes are painted with the same colour. R is painted with orange colour. S and U are neither painted with white nor grey colour. P is painted with black colour. Q is not painted with white or blue colour. Box S is painted with which colour?