Colour Slide is a puzzle in which you have to separate the two sets of coloured counters, so that no two counters overlap. The red counters slide row by row, and the yellow ones slide column by column. Where two counters overlap, you see an orange counter, and when the puzzle is solved there will be no overlaps. Just drag any counter to move it and the counters of the same colour in its row and column. Seems like it ought to be easy, but it's harder than it looks! The usual options to undo and solve are available. You might want to start by tapping the white flag (solve button) to see how it works. The options screen allows you to change the puzzle difficulty, and you can also change the colours if the defaults are hard to see. The game is mouse-controlled. Just drag a counter in the correct direction to move it and the others in its row/column. (The current draggable colour is shown in a large button, you can also click this to change it.) Click the top triangle button for a new game. The other buttons are Undo, Hint, Solve and Settings. In Settings you can adjust the difficulty as well as sounds and colours, and also access instructions.