A new method for adapting digital images so that they are suitable for color blind viewers is presented. In contrast to earlier automatic methods which formulate the problem of adapting images for color blind observers as one of optimization, we demonstrate how it is possible to allow a user to compute a very wide range of adaptations in reasonable time under the control of a single variable. We demonstrate how the algorithm can be delivered as an adaptive technology via a simple interface, and evaluate the efficacy of our method using psychovisual experiments with simulated color blind users and a standard color vision test. ACM Classification Keywords H5.2 Information interfaces and presentation: User interfaces ? Graphical user interfaces. General Terms Algorithms, Design, Human Factors. Author Keywords Adaptive Technology, Color Blindness, Interface Support.