I am a addicted to certain kinds of sonority and tone colors. I guess what I try to do is to make the music sound chromatic, but using mostly the notes of a diatonic scale. I decided to stop worrying that all my songs sound similar, since I am only writing for my own amusement anyway. I am impressed that I can do it at all.
I am writing this new song and Ab, with the Bridge a fourth up, in Db. At that point I will know most of the flat keys (F, Bb, Eb, Ab, Db...) and all the accompanying chords that go along with those keys. I used to wonder how a key could have six flats if there are only five black notes on the piano. I still wonder that. I guess I know how it happens, but it still seems odd. But any way, Db, with five flats, will basically give me command of the entire keyboard, so I won't worry about Gb /F# for now.