White Widow turning purple?

This is my first grow so I don't know all the ins and outs but Im pretty sure WW not supposed to turn purple. Its not the tops of the leaves turning purple but the under the of the first set of leaves a turning purple Barney purple to be exact. Is this a good sign or a bad sign. I know if it gets to cold a plan can change colors but my temp is exactly 75F and Humidity between 57 and 61 slightly changing. Is this natural? Is it too cold or do I have a different strain or is it just fine and let it take its course. The tops of the leaves are a healthy green and they a growing right on schedule not to slow not to fast. Some help would be greatly appreciated. I have the pics of the tops not bottoms I can post the bottom pics later.

I cant tell without pictures really. But this is commonplace if youve got seedlings to see some purple under the preliminary leaves especially if your running cool temps(not a bad thing right around 70 degrees). Keep airflow on your plants bump the temp a couple of degrees and it will disappear to solid green... If there older, could we see some pics so we can analyze... d:rastasmoke:

They are seedlings and it is the primary leaves. I can't get pics up right now but tomorrow I can definitely. I have the temp at 75 right now Im gonna bump the heat up a little on it. Its only 10 days into my grow so Im just a little worried cause I knew about the cold turning plants cold but I asure you its not cold at all. I appreciate the input.

Your a good grower!!! Being worried about every little thing on your first grow is really normal for someone wanting to bring home a good first crop... Marijuana is not that hard to grow but you can love it to death if you know what I mean...:thumbsup: Common plant sense and knowledge of a photoperiod plant is all you need,,, Good luck my friend.. LET IT GROW... d:rastasmoke: