Try starting with pseudocode: it is procedural code with no syntax rules. All you are doing with it is writing down the steps a (hypothetical) computer would take to do what you want to do.
It helps separate what you know how to do from what you don't know -- you know you can assign variables, declare arrays, iterate through arrays, print out values, and call methods that do those things and optionally return values to you. Your pseudocode can use
java statements for that or not, as you choose, make it easy on yourself. But try to create step-by-step pseudocode that does what you want, and then put that in a question. I'm guessing it will help you put a pseudocomment in the code that says something like "Here I want all my Xs to turn blue, but I don't know a statement for that", or whatever it is you're after.
Or you will figure out that, once you have the pseudocode written, you can translate it to Java, at least to give it a try.
Good luck
rc