You can specify colors that do not have a predefined SAS color name by using the RGB, HLS, HSV, CMYK, or gray-scale color-naming schemes. Predefined SAS Colors That Can Be Used in SAS/GRAPH Software ...

Occasionally, authors use a sequence of colors, such as the 'rainbow' color scheme, to represent a range ... whether in color or converted to grayscale, spiral through the color wheel while ...

Why? Well, the answer lies in the GIF below, showing a smartphone switching from a color display to a grayscale one that rapidly extends the battery life. This is the TCL 60XE NXTpaper 5G Android ...