This is a game of chance. It is based on probability, and there isn't a strategy we found that will ensure you always get it absolutely correct. Though there is a strategy we found which can get you close to the answer.
Our strategy is mainly guessing. You have to draw at least 2 time to be confident enough. We usually would draw 3 or 4 times. One of the first things we checked, was if only 3 colours showed we would have to check again. Obviously, if it rarely appeared, that colour only has one or two marbles. Briefly record the draws in your mind to see how frequently it shows up giving you a good idea of what to guess. If there is many of the colour being pulled, then again, there must be about 3-5 of them in there.
Thankyou for reading our submission, it was very brief but we tried. From Sydney and Maika. ^v^ c: