Hi, don't know what the fancy curves are, but for the machines on the second line, one go to next color (on a loop), one "add" two color, another "multiply" them and another "rise" the amount of resources you get on the outputs. To get yellow you have to multiply some and add another...
Indeed the best way to solve the puzzle is to tweak with the colors. The second blue is not really used to "win" but allows you to do some sort of speedrun. But I won't spoil the way to get it ;)