Trouble with custom SmartDashboard Widgets

[Ipiano]

I decided to create some of my own widgets for the SmartDashboard and have been only somewhat successfull. So far, I have taken the source code for the Dashboard and edited the code for the ProgressBar in a new project. As of now the bar works exactly the same except that it also displays the value superimposed over the bar. However, I'm using it for values that range from -1 to 1. Instead of having the bar half full when it is at 0 value, I want it empty at 0 value, full for 1 or -1 values, and in-between for corresponding values. I think I can get that done. BUT, I also want it to change color to indicate if the value is negative or positive(green for positive, red for negative) hoever I am unable to find a way to override the nimbus configuration and change to color at all. Everything I have tried so far has either caused the bar to disappear or not change at all. Please Help!