Why do sunflower seedlings have red stalks?

My sunflower seedlings have been growing well then randomly got reddish stalks/stems. I need some help guys/gals. or:My sunflower seedlings have been

My sunflower seedlings have been growing well then randomly got reddish stalks/stems. I need some help guys/gals.

or:My sunflower seedlings have been growing well then randomly got reddish stalks/stems. I need some help guys/gals.

Tags:stalk,seedling,guy,