Accessing Unprocessed Point Information in Plot Renderer

I have been writing a program that plots points to a Writable Graph. I am working to overload the Plot Renderer so that I can customize how each point is represented on the graph. I wrote a custom point class that stores an (x, y) coordinate position, a Color, and eventually more attributes. I extended the DataTypeDescriptor class so that the point attributes could be stored in their respective buffers, specifically in the method titled: public IList<IBuffer> DecomposeValues(Buffer<PeakPoint> values, Trait decomposeOption). Now, when I am working in the Plot Renderer class, I want to access the attributes of each point.

In the method: RenderGraphCore(PlotRenderArgs renderArgs), I see that renderArgs.RelativeData[0] and renderArgs.RelativeData[1] accesses the processed x and y coordinates (the points are scaled to fit in an area with 0-1 being the range for both the x and y axes). My question is: how do I access the unprocessed point information (ie. the Color and other attributes that I will eventually store in the point class)?

Thanks