Scratch

Hello! I have a little problem. I have 3 scripts, who change 3 costumes randomly after every 4 secounds. My goal is that i have to click on one of the scripts when they are all wearing the same costume, and then the score should go up by 13 points. But when i click it while they are wearing different costumes then the score goes down by 7 points. At the moment i can click on the scripts at any time and the score still goes up. I would like to know how i can make the score go up only when the scripts are wearing the same costume. Also, how can i make the score go down when i click at the wrong time and how do i make the score not changing when i haven't clicked the green flag yet?

Thank you!