Decompresses the HDMA colour gradient in ROM where the table's bank byte is in R0 and its low and high byte in R1. The resulting colour is stored into the Super FX buffer $705800.
Each gradient table is 48 bytes large resulting 24 different colours. The HDMA table is backwards i.e. the first colours are the bottom most colours and the last colours the top most colours in the final gradient.
The first 368 generated lines are smooth transitions where each tenth line is a different colour and the other generated 70 lines are a constant colour using in the compressed table last colour.