school me on squirter cam colors

They change the pump discharge curve. In other words, they can increase or decrease the amount of time and the amount of fuel the pump discharges into the engine. It's generally something you just have to play around with to get the best one for your application. I like upgrading Holleys to the 50cc pump kit. that way, there's no possibility of having a discharge that's too lean. You can always back off the cam, but when you get to the biggest one and need more pump volume, you're kinda stuck.