Would it be possible to setup u new graph type in the form of a traffic light?

The way I see it is the following:

If the last/avg/min/max item value is between value w and x, the light is green
If the last/avg/min/max item value is between value x and y the light is yellow
if the last/avg/min/max item value is between value y and z the light is red

Please let me know when more info is required.