Hello Peter

If you open your project in VeeCAD, go Netlist -> View and select the Nodes tab, you will see the net names listed. These names came from your schematic generated netlist, and can't be altered in VeeCAD.

The net colours tutorial was built from the TinyCAD schematic C:\Program Files (x86)\VeeCAD\Tutorials\Water Alarm.dsn which has the Vcc and GND net labels. All good schematic editors will let you name your nets. For example, in TinyCAD, you can place a net label on any wire. I always label my ground and power rails.

A schematic editor will give any unnamed nets some kind of number. The schematic editor can change the number each time you export the netlist. VeeCAD will pick up the change and move the net colour to the correct net number.

You can set the net colours - go Netlist -> Colours and click the 'Colours' button.

When I go Netlist -> Colours and type into the drop down lists, I can cause an error, just as you report. I will fix the fault for the next release by making the lists non-editable.

Hope that puts you back in charge again!