Thanks for that information.
I don't find the coloring of tags that useful, myself. If there are more than just a few tags, it becomes a chore to recall which color represents which tag. I would expect to have to open the details of the transaction to find out which tag(s) it has associated with it if I couldn't recall the color shown on the summary line.
I would find the ability to create multiple groups in which I could define multiple tags a very useful feature. Please do consider this addition. I look forward to it.