The array returned by this method contains ContourData objects, which have the ContourValue MajorColor and MinorColor properties (among others). The MinorColor correctly returns the color assigned to that contour range. However, the MajorColor always returns color 255, regardless of what it is set to when creating, or editing, the Analysis in C3D. So there is no way of knowing what the color is really set to.
I have found this mentioned a few times from other developers, @redtransitconsultants is one that I recall, but do not recall seeing any response from Autodesk. This affects ALL versions of the C3D .NET API, and really makes our tools look bad, as customers think it is we who are not doing something correctly.
Please get someone to fix this, @dsimeone I'd be willing to bet that it's not more than a few lines of code needing to be changed. Having it updated in a Service Pack, or Hotfix, for 2016 & 2017 would sure be a win.
Thanks for this report Jeff, we'll investigate it.