Two of the squares of a \(7 \times 7\) chessboard are painted yellow, and the rest are painted green. Two colour schemes are equivalent if one can be obtained from the other by applying a rotation in the plane of the board. How many inequivalent colour schemes are possible?
Please note that... (drum roll) this is not original wording. "Colour" was spelt "color", but I, being a true Englishman, changed it to "colour":)