The timer does assume that channel 1 is the soft channel (grade 00, 0, 1, or a lot of Y for a dichroic head) and channel 2 the hard channel (grade 4, 5, or a lot of M for a dichroic head).

Whether you use grade 00, 0 or 1 for the soft, or 130Y, or 170Y; grade 4 or 5 for the hard, or 130M, or 170M: it doesn't really matter; just choose something that works for you and use it consistently.