Loop over all the 120 LEDs, and (assuming the index in the for loop is 'i') take i%6 - that will give you a number from 0~5 corresponding to the position of that led on the board, which you can use to look up what color to make it.
Loop over all the 120 LEDs, and (assuming the index in the for loop is 'i') take i%6 - that will give you a number from 0~5 corresponding to the position of that led on the board, which you can use to look up what color to make it.