Press the corresponding arrow key when it shows on the screen (e.g. if it's pointing right, press the right arrow key) If you take too long, you'll lose, if you pick the wrong one, you'll lose.
So I decided to use the colors from @-Abstracta-'s Palette picker to make a game! First game in a long time. I used the music from a project by Kurubai, her 100 followers special. kthxbai