How are the Min and Max color settings determined for the Single Value visualization in Splunk 6.3?

Hello, In the new (6.3) version of Splunk, the single value visualization can be set with specific colors depending on a min/max range setting. **Questions:** How is the min/max setting determined? If I need to use two colors, one representing negative values (ex: -5) and one representing positive values (ex: 5) how would this be done given that whatever number is input for min-# becomes the min for the next max value (ex: min-100, 100-Max)? Can you only assign these colors to numerical results or is there a way to assign them to strings in the xml?