dance game player

[CarlFK]

I'm looking for guidance in making a game player:
game shows a row of 6 red and blue dots (colors are random)
below are a single red and blue dot.
goal, tap the 2nd red/blue dots in the order of the first row.
Once the player taps 6 times, screen clears and another row of dots.
game runs for 60 seconds.

I get how to do image selection on the first row. I think i will need 12 - look in position 1 for red, look in position 1 for blue repeat 6 times.

If it sees red, tap the static location where red is on 2nd row.
if blue, tap blue location.
repeat 6 times.

What I am confused about: What defines the order the images are detected?

What keeps it from detecting the same dot and clicking more than once?