Leaf Vein Colors, any significance?

[dangles]

Does anyone know if leaf vein color has any significance? Can it be telling of anything such as plant health, or can it be related to the strain?

 

[BryanOconner]

usually temps being too cold super high Ph will also effect that . Pics ?
Strain yes only if you get the temps down they will change colors like purple . Warm they wont change colors . I have to say usually i have never seen them change colors over 75f