there are 150 center pieces which show one color each, 60 edge pieces which show two colors each, and eight corner pieces which show three colors each. each piece (or quintet of edge pieces) shows a unique color combination, but not all combinations are present (for example, there is no piece with both red and orange sides, since red and orange are on opposite sides of the solved cube). the location of these cubes relative to one another can be altered by twisting the outer layers of the cube 90°, 180° or 270°, but the location of the colored sides relative to one another in the completed state of the puzzle cannot be altered: it is fixed by the relative positions of the fixed center squares and the distribution of color combinations on edge and corner pieces.