Color Scale Use the radio buttons to select the scale for color separation. Select: When you want to: Normal Separate colors based on a normal distribution with equal probability. This selection is normally made for log-transformed intensities. Percentile Separate colors based on empirical percentiles with a fixed increase of percentage. This selection typically provides a more balanced color display in the pseudo image. To Specify the Color Scale: Click the radio button corresponding to the scale that you want to use.