yeah, I was going to say, it is more than likely the light, I had mine and I thought it was over watering, but like you said, the leaves were not turning yellow just purple, which a little purple is fine, but depending on the type of pepper it will hurt it more than others, like my chocolate hab has it's cotyledons that are bright purple, but the rest of the leaves are a nice green, but I had 4 CFL lights 3"-4" or so from the plants and I was freaking out because they were turning a slight purple, but like you said, a purpleish/brown, (and I have burned my plants before from too much light when I first started, I had my 130w XtremeLED about 3" from the plants and I had measured it later at 132,000 lumens at that distance lol, but most of them recovered)
but anyways, from the new seedlings I have coming up they were looking bad no matter how much I changed their watering schedule, so I turned off 2 of the lights after measuring that the lumens were about 30,000+ lumens hitting each plant, so I backed the lights up a little and like I said turned off 2, so I think it is more like 10,000 lumens or so for them, but point being that at least until they get a couple of their true leaves, I have noticed that you can hurt them with too much light pretty easily.. I think most people don't have problems with this because either A.) they actually do water too much and that tends to hurt them more, or B.) they just have lights that are either not as strong or as close as at least what I have been setting them at, and it depends on the enclosure too.. but anyways, back the lights off or turn some of the tubes off or something, but reduce it and they will start to come back within the next day or 2.. at least the new growth will, the old growth will still look kind of crappy depending on how damaged it was.
and just to show you exactly what I am talking about, here is a pic of the seedlings back in Dec. when I had them under the LED super close lol
and here are 2 Tscorps that I almost fried, this is about about a week or 2 after turning off the extra 2 lights (probably just a week, but it seems like 2 weeks lol), the leaves you see that look the worse were actually starting to turn whiteish almost.. from just being bleached from the light (the 2nd pic was with the flash on and the camera battery died right after that, but you get the idea..)..
--and no to anyone who is thinking it, but they are not being over watered.. I just sprayed them a little bit an hour ago. which is why the soil looks wet..(they are slightly yellow from the fact that like I said, they use to be almost bleached, and the flash/CFL lights are giving them a lighter color than they actually look like in person)
hmm, can't get the 2nd pic to rotate, it is rotated in photobucket but oh well..
