is a redish color on the branches ok?

Hi umm first time posting here lol but learned a lot from all you guys here. Anyway my question is this: all my leaves look healthy no signs of nute burns, deficiencies etc but on most of my upper branches its almost like a thick red line going up the branch but stops at the leaves. kinda looks like the nutes got sucked up the stem and up into leaves only burning the branches.
Also they aren't completely red either like i said looks like a thick red line. I'm about 13 days into veg for this plant hasn't had a problem with the nutes till now if it is that and i've been giving full dose plus since seed(bagseed was just experimenting but it liked it and exploded never showing nute burn).}Seems fine, healthy, growing quick just wanted to know if it was something i should keep an eye on.
Any input much appreciated. This is a cfl closet grow btw.

could be cooler temps, could be genetics!

Is it on the underside as well? on the veins of the undersides of the leaves?
It could be Phosphorous deficiency. It also can be genetics, but even when it's
"genetics" it is because genetically the plant wants more phosphorous
than your other plants.

Thanks for the quick replies guys just checked on it and it def does not go into leaves at all and is actually only on the topside of the branch. As far as temps go its def up in mid 80s right now in their so i dont think its to cool.Well i have some heavy duty nutes with phosphorus in it let me see its umm 10-52-10 it had a full dose of that and 25-10-10 as a seedling like it was a couple days old, and continues to get the 25-10-10 every time i water(like i said it started out me experimenting but it liked it) so idk you think i should throw in some of my high phosphorus nutes to the mix?

what about night temps?

night temps prolly only get down to 70 F at lowest, as my apt stays pretty warm at night with heat on lol. It is cold outside though(canada =) ) but closet not located on an outside wall and like i said i put heat on at night so i don't think temps are my problem.sooo idk....

prob genetics pal! keep an eye on it, some great threads on here, have a go on the searchbar!

Alright ill just watch it ,thanx for help guys and ill take a tour through see if i find anything looking similar.