problemo? please help?

hey...on like the 4th and 5th nodes, the stems are purple on the top and green on the bottom...the lower leaf sets are green... but the top ones look like they have some sort of defficiency....lets me reword it...halfway around the stems(facing the light) are purple...the other half (facing dirt) are green...anything anyone can diagnose? it's not it the plant disease,etc. section...:joint::joint::joint:
 
using a shitty coralife fluorescent at about 2 inches away..the 150watt hps comes tomorow. could it be lack of light? it smells pretty dank, though, and it's not even close to flowering
 
Top