I can imagine! For myself the drawings I color mostly takes hours for each when I add shades and light and so on, and as for Piti's drawings which are so thorough I almost can't imagine how long it must take for him. I admire him a lot for that, and the fact that he makes them looks so good just impresses me even more!
He never seizes to amaze me with his amazing works! ^^ I hope he doesn't push himself too hard though ;3