I want to look into the nutes you are using. Botanicare has three different lines for nutes.
Kind, Pure Blend Pro and CNS17. Which are you using?
Cold stress can certainly bring on colors like your plant is displaying. You mentioned that the temps are between 71-75°. Is that during lights on?
Do you have an instant read thermometer? A digital meat thermometer would work. I would take the temp of the water. If you normally set it out or take it straight from tap,do the same steps you normally would. I would also check the soil temp through the bottom drain holes. This is something that you would do right at lights on, before the lights heat up the tent.
Your pH may also be playing a part in this. That is a large pH range. If you must pH I would keep it between 6.2-6.5ish. This pH range will give your plant the best possible access to it’s nutrients. Anything above 7 is just too high of a pH.
You may need a slight tweak in the pH department and are possibly having a small temp issue.
I’ll check in later. I have a bit of a busy day ahead of me.
Have a great day.