PuRPle LeAvEs???

Okay so I have this plant is veg and it's leaves are turning purple. Not because of the strain or the cool temp. SOMTHING IS WRONG! I look it up on google and it's some diffency. It kinda talks about but I can not find on how to help the problem or solve the problem.
Please roll it uppers
help me!!!

potassium def to some extent can turn leaves purplish.

I know that its possible a def...... I need to know how to fix it