When Elisa is undercover on the train, in a blonde wig, her eyebrows are also colored yellow. As soon as the wig comes off, her eyebrows go back to their usual black color.
Demona is shown in flashbacks to 994 with one of her "old" animation models, from when her face was long and sagging, with deeper lines. At that point, she should still look like her original, young self, as that scene takes place less than a year after Goliath and the others were put under the sleeping spell.