The ability to specify a custom range for the gauge widget would help to visually communicate whether the shown value is above/below normal.
For example, I use the gauge widget to display room temperature. When the room is 23 degrees Celsius, the gauge shows 23%. If we could customize the gauge range, we could configure it to show 23 as the middle point, and anything below or above that number would be reflected accordingly by the gauge indicator line. And if you wanted to get really fancy, you could configure the gauge line to turn blue if below and red if above… Maybe a dedicated temperature gauge widget would help, similar to how the sensor widget has pre-configured options for motion, door, etc.