@misar
The difference is that the underground line names have been well known by nearly all users since time immemorial, whereas right now the overground line names do not mean much to many. With time they will become more familiar. My question really is whether something a little more could have been done to help during those first few months of familiarisation.
Right now, if I see the list of new lines, I have to think about where they go and that’s not really what a customer information website should be about. For all I know it was considered and potential solutions rejected as too clunky to justify something which would not help the majorty of LO passengers.