Hey so I am somewhat expirenced at gardening but really only know the basics. I am growing the Carolina Reaper, Muruga scorpion Trinidad Pepper, and the Chocolate Bhutlah. I have noticed on a few of them the leaves are turning a ash color NOT black and crumbly and my plants arnt leggy so I am not sure if this is bad or not.
I grow indoors with plenty of room have a growlight about 4 inches away from the plants and I have the light on from about 7AM to about 9:30PM. I water about 2 times a day when the soil is very dry and crumbly.
Another thing I am not sure of is it safe to grow these peppers in a seedling starting mix even though they are now plants? Could this be why they are turning this ash color?

Welcome to Garden.org, @Chewman5252 !

The leaves kind of remind me of spider mite damage that I've had on some young plants -- have you seen any tiny webs on the plants? Or, if they are still in the seed-starting mix, maybe they just need a little fertilizer.

The only difference between regular potting soil and seed starting soil is that seed starting soil is finely milled and it doesn't contain any fertilizer. If it was lack of fertilizer, the leaves on your peppers would be turning yellow. The leaves look water-logged to me - are you letting the plants dry slightly between waterings? Two times a day seems excessive.

The soil looks very wet. Am I seeing that the plants are being grown in a small amount of medium in small styrofoam cups? Perhaps the plants might like a little more room for their roots and larger pots with better drainage.