1. A method of processing image data comprising storage means, processing means and display means, wherein said storage means is configured to store image data as picture screen elements having colour components and said processing means is configured to perform the steps of: generating a three-dimensional space representing a colour spectrum containing said colour components; initiating a plurality of three-dimensional space forward transformation matrices and at least one backward transformation matrix; concatenating said three-dimensional space transformation matrices to initiate a single three-dimensional space transformation matrix; populating said plurality of three-dimensional space transformation matrices in reply to user input data; and adjusting said image data by means of processing each of said colour components with said single three-dimensional space transformation matrix, wherein said backward transformation matrix omits the last forward transformation matrix applied.