Element ID's in list

Can anyone help with working with list?

What exactly are you trying to accomplish? If you just want your Ids to be green you can’t really do anything about that. That’s just a Dynamo thing to help identify elements.

You can reselect the Revit elements with the IDs. Your input would be the "newList" output.

More info here:

Archi-Lab also have a node to do it “Select.byElementId”. If you prefer it.