-Light is important - it's bad enough in the winter even by sunnier window. Solution could be some supplemental lighting. -Colder temps should not be so much problem as long as you are not overwatering. (I have most of my succulents in 58F and next to old leaky windows, but am careful about watering. It takes longer for mix to dry out if colder.) -What did you transplant into - what kind of potting mix? -Plant may be underwatered if in wrong mix - again, what is in your new mix? Rina

I am not sure if it got frostbite or not - it looks rather dry? What was the lowest temps you left them in? "Ideal" temps are listed as 50*F for low. I have seen other sites suggesting min as low as 20*F - I don't not know who is right on. Frostbitten leaves, at least in my experience, fell sort of 'gummy' - I am not sure how to better describe them. They also fall off easily, maybe not immediately but soon. Stems in first pic look better than stem on right in 2nd pic. Does it feel soft and maybe even mushy? Or dry and hard?

That yellowish flesh may have been ok - I am sure I said somewhere that usually it is greenish color, sometimes more creamy. What you do not want is dark spots, of any size or shape. Dark like brownish or blackish. But do not worry. Let cuts callus for a while, and after plant them in dry mix. I usually do not water root-less cuttings for a while; 10 days, 2 weeks or longer. I start watering when I see some new growth - sign of roots growing. (I already said that too - sorry for repeating). Some ppl recommend spritzing with water after few days. BW, I usually trim off that longer piece of trunk from cutting too, just as I suggested where to cut from trunk. It just dries up and heals over faster. Not everybody does that, and that is OK too. What I mean is to trim off excess below the collar. Hope you understand what I mean - if not, just ask. (I just added a photo where it is quite well visible - see end of this post). You could lightly dust the cut with flowers of sulfur, or powdered cinnamon,.but not absolutely necessary. Those are fungicides. Here is photo of one thicker branch I did (I very seldom do it anymore). This shows darker flesh because it is already callused, and I used powdered cinnamon - not because there were dark spots! ETA: here is photo of thicker branch, just cut (before callusing). You could also see how far from the collar I trimmed it:

That is most likely a good idea. It is either drying up or rotting. Roots will tell you. I have C. mesembryanthoides, and keep it under lights during winter and water about 1/2.5-3 weeks. But it looks better outsides. I have a feeling that it doesn't like indoors much, since it does loose bit more leaves, but not all. They just dry up to crisp. Photo below is from September, still outside. It is in very gritty mix.