Why it red... This strain shouldnt be red as far ...

And it's several weeks off for harvest, imo. Just elaborating on the effects of the cold... So basically, your plant's metabolism is like in stasis. Coz it can't get nutrients externally from roots. What it does then, is use the mobile nutrients it can (esp phosphorus at that stage) from parts of the plant itself, so it depletes its own internal stores, thus purpling (along with small size).

Ok next to the red you also have some drooping leaves and som tips clawwing and white. The clawwing is sideways but I suspect its several deficiencies. Because of either PH out of range, too much water and not letting it dry out more, your plant cant take up the nutrients. So dont bother adding more to the soil for now. Just do good clean PH water to flush. Then let soil dry out. Dont feed the soil again, let them flush till harvest. In the meantime to save the leaves and make sure the plant has what it needs for budproduction, make a half liter of PH 6.4 water that youve added to: a phosphor containing fertilizer, some epsom salt (teaspoon), but the main reason for the reddish hue is: potassium shortage. So also add some baking powder, BUT: dont let it in too much light or heat after that. And be mindfull that you need very little baking soda and that it will bring your PH down enormously. So after that PH minus it again. Let the leaves absorb this but do not spray the buds. This way you can extend the plants nute uptake w/o risking flavor

Just looked through your last few weeks. It says your day temps are like 18 and 19 deg. The purple is probably due to low temps if its not in its genetics. Ideal would be to get up to at least 22deg during day.

p.s plant looks like - need more 4-6 week to harvest

1) low temperature (under 10-15c) 2) phosphor deficiency (i think this is your problem)