I created a KPI in Powerpivot 2013 using as a base a measure defined within the workbook. The KPI definition uses an absolute value vs. a calculated value. The problem seems to occur when there is a wide range of possible values - in my model 1 - 150,000 and the 'absolute' value is towards the lower end of the range. In the model, the 'green' threshold is set to < 100, the yellow threshold is 100-500, and the red threshold is > 500.
The problem is that values are showing up flagged as 'green' when they are not - they should show up as yellow. I've played around with the absolute value setting and the thresholds and only when all are set high enough does the color coding work correctly. A chart is included in attachments that shows the results with different absolute and threshold settings.