I have Networx app icon in my tray area. The problem I am having is that when it is in Histogram mode, the background is clear and the graph is very hard to see. If I use thin or thick bars mode, the background goes white and it solves the problem. But as soon as I switch back to histogram, the background becomes transparent again.
It is indeed a small issue. It happens due to the code that draws the histogram treating pure the white colour as transparent.
The simplest solution for this is to go to the Graph Colours tab in the NetWorx Settings and choose an off-white colour for the background (e.g. Ghost white or Snow). It will look white in your tray/notification area, and will fix the problem.