Rookiegrower710

I have a Blue Dream plant that was started as a clone inside. I put it outside over a month ago and see that all the stems are purple. They were purple inside so I assumed they would stay purple well, the new growth is coming out green. I didn't know it may turn purple but was wondering why do stems turn purple? {"data-align":"center","data-size":"full","title":"Purple Stems","src":"https:\/\/drive.google.com\/file\/d\/1Q7vlFUl6g0yKOM0dPQc7EvE2Nz0ar4wk\/view?usp=drivesdk"}