People say it's a P deficiency, but it happens to me when my lights are too close to the leaves for too long. So, too many light hours.

Have you fertilized them at all? They look starved.

Rodney

Agree with Rodney they look like they have been over-watered (a chronic problem when using peat pots) and under-nourished. What and how much have they been fed? The purpling is normal for young plants under stress but the yellowing and the anemic veins are not normal.

Dave

They need nitrogen and more light.

I also think they need Nitrogen and maybe "P" too.

I think that Purple color can be due to :

--- variety

--- Cold ambient temperatures

--- Phosphorus deficiency.

I could be wrong .

Sey