Yes, it's a tribute to the fundamental balance of the original. Those were based on simple filters mass applied to the entire theme (desaturation for PoD, inversion for CC and invert-lightness/keep-colour for BS). I did it that way because Bloc hasn't released full PSD's to the team yet and I just wanted to have some fun without it becoming a major undertaking, and those combinations worked best. Of course I still had to do some custom icons, plus the css for link colours, etc.