Red leaves

Its natural

W widow does tend to have purple leaves, mine did too. They look healthy, they don't look dry or brittle. So carry on. Lower temps especially at night will bring out the purple colours.

And the reason I say I think it's more likely phosphorus, is coz of light, relative utilization/flowering stage and phosphorus' function, as the basis for internal cellular energy. Which is also why it's related to cold temps.

JoeyGonz "The change in color is generally attributed to the appearance of anthocyanin, a water-soluble pigment that plants generate either due to their genes or due to potassium deficiency, and low temperatures can also mess with color." It's not necessarily potassium, imo it's more likely phosphorus in that case. But anthocyanin production is affected by a number of factors including potassium, phosphorus and nitrogen. Typically I find it associated with phosphorus related issues though. It is not necessarily a bad thing and is fairly normal as the plants mature, so they use up energy/nutrient stores in the plant, phosphorus for instance, is very mobile and pretty heavily utilized in flowering.

That looks so cool :) Its completely natural shes just showing her colours and she has alot to show clearly :) Beautiful plants :)