I dont care if this is old, some newbie is going to find some of this bad info and ruin thier plants. Temperatures just below 50f the last two weeks of flower brings out the fall colors in phenos that change color. Not all do. Thats all it is, fall colors just like trees outside. If your growing outside just let your plants get down in the mid to upper 40's. Do NOT let frost get your plants, that is 100% terrible advice and practice. Frost causes damage to cannabis, even though it can handle some cold cannabis is not cold hardy. Freezes kill the plant and the fallen seeds grow next year. Cold hardy plants go dormant then start growing again when temps remain above 40f for two weeks. Cannabis are not among these plants. Frost freezes trichomes and makes them brittle, this degrades the potency period. Just because the plant may put on a little new growth after that it does not make it more potent. Each time your plant freezes or frosts it causes damage. Like I said, cannabis is NOT cold hardy. Its a crop, does your tomatoes or corn come back the next year? No! Some seeds that fell may grow but the plant itself dies. Indoors temps just below 50f for the last two weeks will bring out fall color in strains that change color in fall. Again, not all do. Never store your buds in the freezer for the exact same reason. Glass jar, cool(not freezing) and dark is how you store buds properly.