Looks fine mostly. If its not as blue as before? That's what happens when growth slows. Color with these tells you if its growing great- rich blue. When that blue turns green or worse yellow, its not happy. Color lost will not grow back..but will return on new growth if you turn things around.

I find that they like a richer potting soil(with FAST drainage) and consistent watering and -horrors!- Pilocereus like summer fertilizers.