WS2812B Fastled Theater chase

Yes, it's not that easy. The test "if 'millis()..." acts as a chronometer. If you want more than one, you should add more chronos as well. S maybe copy all the if block (the lines between the {} including the if) and change the 1000 to 2000, 3000 and so on. And of course as you did use index2, index3...