FFOF & dry ammend. i think I was overfeeding at first, too much Fish n kelp. Now I just top dress 2-8-4 every 3 weeks & water. Nothing else, except molasses tbsp & fish sh!t. Strain is NL1Doesnt look horrible. Could be a lot of factors.
What strains, what are you feeding, are you using calmag? Looks like theyre fading a bit early but you shouldnt have issues finishing them out i dont think. Some mote info would make it easier to help you out. The black/purple could be genetics or it could be temp and humidity related.
Are you over feeding?