My kessils only have blue and white and they get good coloration. It's your parameters. Phosphates did it to mine at first but recovered since then now they are better. Big water change and keeping a consistent ph alk and cal
I know you want phosphate as low as possible, but what is getting in the bad or danger zone? mine with my phosphorus hanna checker was 85 then i multiplied it by 3.066 then divided it by 1000 and got 0.26061. is that ok level? any help would be greatly appreciated. thanks in advance.