Hi, I'm wondering now if you can guarantee a white beam if you pay close attention to the bar and make sure it only fills up 1/3 of the way for each color? I usually start w/the blue and then the red and end w/the green. The reason I'm asking is I have a sim at univ and as much as I try and get it exact, she has been getting a blue beam. I tried starting w/the red pad first once and got a red beam. Do I have to have 3 sims working on this at the same time? There have been a few times when she has gotten the white beam, but lately, ugh!