Despite popular belief, color vision disorders do have an impact on the life of the persons affected, on both professional and private, everyday level. It is important to be aware of the possessed disorder, as in severe cases color-blindness may even endanger one's life, as e.g. protanopes may perceive red traffic lights as extinguished. Computer games and simulations, although broadly present in medical education for at least fifteen years, have not been yet used as an accepted diagnostic tool. This article discusses the possibility of using serious game for diagnosing color vision disorders with a author-developed disorder-dependent palette of colors, which are difficult to tell apart by colorblind. An experiment, involving simple web browser based game was conducted. The analysis of its results are discussed, especially the problem of false positives and negatives, which is always present in automatic diagnostic systems.