I've suggested this multiple times in the past, but...
I remember that as while the candle's flame sprite can be selected in the item editor data, the flame sprite for the Book and din's Fire is hard-coded to use the default Link Flame weapon sprite, which I honestly don't think makes much sense at all! I have often stated that the flame sprites for the Book and Din's Fire should be customizable in the item editor, just like the candle's flame sprite. And I think that making these adjustments wouldn't be any problem at all. In this case, the Book's flame sprite would have to be set to weapon 2, and the flame sprite for Din's Fire would have to be set to weapon 5.