Nice game ^^ It's very relaxing.
There a few issues for me though you can improve on:
Having to go back to the start just to change color is kinda tedious.
The collision with the colored block wasn't working for me. I don't know why but I had to bump a few times on it to get through.
The character start to shake at some point. I actually know a fix for that. You are probably using physics to move your cubes, either changing velocity or using addforce. This makes the position of your character change during the fixed update. However, the camera is by default actualised during the late update. If you switch your camera to fixed update it will work.