But you talk about "The purpose is to have different lines/coloring for each line". That implies to me you do want multiple, separate line series, each with their own points and color?
In that case you do want new QLineSeries created each time round the loop, so you end up with 5 lines (and get rid of the wasted one outside the loop).
Okay, thank you. I did this and with a little bit of refactoring I got it to work as expected. Appreciate the assistance!