Normal sudoku rules apply. Divide the grid into grey and orange regions. A region is a group of orthogonally connected cells of the same colour. No 2x2 area may be all one colour. Two regions of the same colour may not touch diagonally. A digit on an arrow cell indicates how many cells you have to travel in the indicated direction until you reach a cell of the opposite colour. Eg: if an orange arrow cell contains a 1 then the neighbouring cell in the direction of the arrow would be grey. Two orthogonally adjacent orange cells must have a difference of at least 4. A small clue indicates the number of cells in the region. In a cage, the sum of orange digits must equal the sum of grey digits. Digits MAY repeat in a cage if allowed by sudoku.