my suggestion is closely related to this question
I would like to suggest that, by default, you include no standard categories, or at most two (like work and personal), since (by all respect) 95% of your default categories suck. I know, I can delete them...
Anyway, in my opinion, my suggestion makes sense. Let the user choose, which categories he needs. In addition (in fact, this is my main-proposal and much more important than the other), let the user choose, which icon he wants to use for which category. That can't be that hard... For each category, the user should be able to click on one of your many icons and thus choosing it.
I think that would not be much effort to implement (but, of course, I could be wrong), but would be much more useful to almost all users (like I said, there are so many useless categories). And if I define new categories, I don't have a symbol for it.