I will always love and appreciate this app, and judging from the other reviews people seem to love the new study system, but with the new update I'm feeling a bit confused. Previously, it seems like the app used your performance during study mode to automatically sort cards into color-coded lists. For example, there was an option to set "Green" to mean "learned", and if you answered correct on a card enough times, the color highlight on the card would automatically change to green. If you set "Red" to mean "forgot", answering a study card wrong several times would automatically mark the card red, and it and show up on the "Red" list.
With this update it seems like the option to set colors to "mean" anything is missing. I had a long (~600 cards) list of kanji carried over from the previous update, all highlighted in different colors according to whether I had "learned" them, vs "memorized" vs "started", etc. When I study the cards in the new study mode, the highlight color seems to no longer change according to how well you do on the study mode. I decided to reset my study progress which, by way of the old version of the app, should have emptied the "Red" and "Green" lists and changed all the highlight colors back to default white, but this did not happen. I don't know exactly why this changed with the new update-- I think the new UI and everything looks great, but the auto color-coding feature from the old study mode was much more functional.