This button opens a popup window which allows to chose one of a set of predefined colortables (see Fig. 5.15). The colortable can be stretched at the bottom or top, or a Gamma correction can be applied. Note that this option applies the gamma correction to the colortable, whereas the Gamma setting in the SM_GUI main window (see Sec. 5.5) applies a gamma correction to the dataset. The two are independent, and their effects add up.