Color studies of Nigiri and Makis from a tiny little 6-7 seater Sushi Resaturant in Osaka I went to with friends in 2019. The place is called Sushi Nakamise 鮨 なかみせ. I highly recommend going if you can, it is an amazing quality and experience at a very affordable price. Unfortunately the owner couple doesn't speak english, so you'll have to speak and order in Japanese.