actual you can using mkds editor for pallete file (nclr), is more easy replace color import from pal files.
If you want expand sprite you must know about OAM. Sprite is have many type, is need segment command, need cell, narn and ect. If you want arrange that , you must know what is OAM, know hex editing, pointing, animate frame, arm addressing on emulator and ect. I was see some hacking project on gbatemp, yeah on translation project. Most of them using ct2. And some need hex editing because is need expand on some segment/cell.
Yeah i waiting too abacus about you tutorial yeah changing pallete is easy one for newbie soo not confused than other