Beginner Gardening: Uh,oh! The leaves are turning color!, 0 by kris_OR

kris_OR wrote:
...and the veins on my gerbera daisies are turning red. The red then spreads to the rest of the leaf. The underside of the leaves look better than the topside.

Is this something I've done, planting it incorrectly or placing it poorly, or is this a disease of some sort? How can I make my plants healthier? Anything anybody can tell me is welcome, even if it's that I completely screwed up.

Thanks!