my babies stems and leaves are turning purple

they are healthy dark green looking but there stems and leaves are turing purple. i dont know if the temp has really much to do with it but there out side plants i stated them from seed sometime in december and its been getin really cold out here like 40 degrees and below but its FL so most of the time it stays hot in sunny so any help

Yeah 40F is well below what the plant likes as a low (60F). Your plants should be fine, just make sure you cover them if it gets below freezing.

as long as it doesn't frost your good but like purp said you should cover them, as for the purple all that is, is the chlorophyl that comes in as it gets colder there is no prob with the plant or the purp could b from a color-changing strain either way your good... good luck