I lost normal mode with 96.6% and barely won hard mode in the last try. I really like this game, it's very challenging. The only part I still don't get, is th

I lost normal mode with 96.6% and barely won hard mode in the last try. I really like this game, it's very challenging. The only part I still don't get, is the colour mixing additive or subtractive? I played assuming it was additive (because we're on a computer) but now that I read your comment in the OP I'm no longer sure.