One possible way is to hack the palette with a hex editor, screenshot when the sprites you need are on the screen, take the sprites from there and then recolor them when you put them on the sheet.
http://www.zophar.net/fileuploads/2/10690nxpfq/AoRH.htm
This can help.
http://www.zophar.net/fileuploads/2/10690nxpfq/AoRH.htm
This can help.