It's got a good theme and vibe to it, and I do like it though it pushes me away quite quickly.
The needless amount of buttons to change hook colors is silly, then on top of it you get dinged for missing even a single fish which at times seems impossible to catch all of them with the cool down and having to swap via different buttons every single time. I wasn't even able to break the 100 mark and it doesn't instill me with the want to do such because of how the mechanics work.
Either there needs to be more leeway with missing fish, or you need to make it simple, one button three colors. You have to swap between them to catch but not have to needlessly over think which button triggered what color again? That and saying you wanted to keep the color theme idea. Move the buttons to change into a more uniform placement. A S D Those three could change the colors which makes them uniform not above one another not needing 2 per color etc. Complex doesn't always make it better especially in games where it's like this, but eh that's my take on it.
Relax mode also seemed not to want to work unless it's meant to just sit at the main screen doing nothing.