saturated_rainbow(n, saturation_limit = 0.4)The function defines a saturation limit, above which the color remains bright red. The saturation limit is set to 40 items with the largest relative proportion in a sample. The default value seems to work well for a wide range of circumstances -- it allows items that are strongly dominant in a sample to be identified across the plot. Ideally, the total number of red squares should be kept low, never more than one per sample.