if you dont get a answer here maybe try the heirloom area or the tomato area of veggie forum
http://forums.gardenweb.com/forums/heirloom/

Sounds like phosphorus deficiency. See if this looks like yours. Picture is about halfway down the page.

Here is a link that might be useful: Purple leaves

Yep, hollyclyff that's it.Thank you.I like this forum better 'cause people are nicer.

At the small seedling size, I think all you really need is
to do is wait for it to warm up. The plants will "recover",
just fine when planted out.

Lee