Cannot change the color of selected nodes

[oxy86]

Create or load a network.
Click a node or select some nodes via mouse.
Open Node Properties, change the node color to another one.
Press OK
The node color changes but only until you click somewhere. When you did click something, the node color changes back to the one used before you made the change.
This only happens on the canvas. If you save and load the network again, the correct node colors appear.