Curious about attack colors

Each of the five colors has a color it's strong against, right? Red, green, and blue are strong against each other, but purple and yellow are separate. When I don't have a color to attack, I've been avoiding the weakest color or the same color. Am I doing this right...? I want to finish Season 1, but it's getting harder and harder ㅠㅠ I think the beginning of Season 2 is easier.