Hi @Gabogom,
To create a range of color in any graph, right-click on the Y axis, choose "Axis Settings", check the box "Allow ranges" and specify the min and max values with the color associated to the range:

Once you click on OK, the range color can be seen in the Prediction Profiler (or any other graph you want to customize):

Hope this answer will help you,
Victor GUILLER
"It is not unusual for a well-designed experiment to analyze itself" (Box, Hunter and Hunter)