Red Vains And Stem

My plants have a very deep almost look like blood flowing thru them in the stem and leaves. Is this normal? Its my first grow so i was curious. Is this a problem or is this something good?

Are the stems red to to bottom. Or just on the upper portion of the plant. I find that if they are just on the upper petioles is a phos. def. but if its throughout, then it could be genetics.

Its normal for the stems to be red or purple.

Could be a def. but if the leaves look fine I have heard that dropping temps will turn them reddish brown. You monitoring your Nighttime temps? try to shoot for a constant 75 all round but no more than 85 lights on and no less than 65 with lights off. Should be fine if you are feeding them properly.