This looks like nitrogen for meCheck your run out on ec and ph next watering
Hybrids and crossed strains may not give you the same phenotypes and grow/look entirely different, the purpling can occur with cooler temps. As far as the dying leaves..was probably just the need for transplanting, constant droopy leaves are also a sign of that.
@Kirr38,i agree. Roots are too developed for the cup. Also for its current size i would put on 15liter textpot