give each series an own color

Change-Id: Ia74eda050349d34d23e07b8e700aaae97e43d903
remove printf statements

Change-Id: I82de8e5e3c028103f1d2b006124593293f9fe365
some work into intercepting mouse events in OpenGL window

Change-Id: I46dcfed7d5398d994c68ed7cfe4408f9f5719bf1