The gauge control has a definable color range if you right click on the control and choose Visible Items>Ramp. The colors and marker locations for each color can be set with the property Scale.MarkerValues. To change the curvature, postion the mouse pointer over either the first or last value until the pointer changes to a semicircle and click and drag to the curvature you want. To rotate the whole range, do the same thing to any of the other numbers on the scale. To change the min or max value, just use the text tool to highlight the value you want to change and type a new value.