VBAI allows you to work with grayscale images only. You can acquire an image, use the vision assistant to convert it grayscale by extracting the luminance plane (or any of the other color planes) and then analyze the resulting grayscale image. To do what you are talking about, though, it would really be better to get Vision for labview. You could then take color images, compare color plains, use statistical functions to determine average color values, and so on.