Congrats on the license.

Your temps are in the 70's. We run in the low 70's for hydro and the cooler climate just makes some strains turn purple. Some have strips on them and some really purple up good on bud leaf. Young ones start all green and then turn slowly or stripe up. Seems to be mostly Indica strains here. Sativa's maintain that green.

As long as they look good no worries. Just keep an eye out for problems.