Usually if it gets exposed to colder conditions then with increased light it is reacting to that stress. By the looks of it, looks okay. As long as no soggy part anywhere there, it should be fine. It can take temps down to 30F and ideally better if kept drier.
Just like one of my jades..that spot gets more full sun in winter, and it has been rainy last winter as well. A few days back got into some hail..so it is looking so cold stressed.
Btw...your plant also looks like it is Portulacaria Afra, and they do grow such reddish stems, so it is quite normal.