Changing the topcolor is more than a simple matter of aesthetics; the topcolor also serves as a signal for whether I am logged in.
I have to say that dfcdfc is a nice topcolor. But don't take my word for it, here is another HNer happy with the tranquil bar along the top:
> thanks for the recommendation on your profile page to use dfcdfc as
> the topcolor; I stumbled onto it over a year ago and have been using
> it ever since. [^1]