It sounds like you might like my answer here: http://programmers.stackexchange.com/a/262847/156217

The basic idea is:

 1. Address the cube in an x-y-z coordinate system, with a center at (0, 0, 0).
 2. A Piece class stores a position `(x, y, z`) and colors `(cx, cy, cz)`. The Piece knows which sticker colors are on which axis (x, y, or z) but doesn't know which direction the sticker is facing.
 3. The Cube stores an *unordered* list of Pieces.
 4. Rotations are done by updating the position and colors of the relevant Pieces.

This is nice because all rotation logic is confined to the Piece class. A Piece doesn't know its orientation, but it doesn't need to. The orientation of a Piece is strictly dependent on its position: the corner at (-1, -1, -1) is the LEFT-UP-BACK corner.