Current Behavior

Given I import a gexf-file which has schema version 1.1. There are only rgb values used for color definitions, for example:
<node id="1789" label="1789"> <ns0:color b="41" g="255" r="0" />...

When I export the graph imported before into a gexf file again using networkx (using nx.write_gexf and with default gexf-version '1.2draft') it adds alpha value "None":
<node id="1789" label="1789"> <viz:color r="0" g="255" b="41" a="None" />...

Expected Behavior

In my opinion it would make more sense to use a default value of a="1.0" to remain compatibility. For example Gephi 0.10.1 can not handle alpha="None" values.

Steps to Reproduce

You can download the dataset Schoolday and execute the following code:
schoolday_graph = nx.read_gexf("data/schoolday.gexf")
nx.write_gexf(schoolday_graph, path="data/schoolday_new.gexf")

Open the saved schoolday_new.gexf file with a text editor. You can see that it uses schema version 1.2 and has every alpha value set to None.

Current workaround:

The current workaround I use is to read and write the gexf-file in networkx like described in the reproduce section. Then I open the file with a text editor and replace all _a="None" by a="1.0".

Environment

Python version: 3.9.16
NetworkX version: 3.0
Gephi: 0.10.1