Day 3
Didn't do anything for this game.
Day 4
Did a bunch of game feel/positive feedback stuff today.
First of all I added a particle effect when you change the colour of something. This especially helps if the colour is white, or the same colour the object already is.
To help aiming the raycast, I added a crosshair. It's a heart because this game isn't exactly violent. I also added an indicator of the current, previous and next flags to the upper left of the UI, as suggested by MisterLee!