I am looking at your images and I am not seeing the vibrancy of their overall color. It looks muted or subdued. I think that a large part of your problem is insufficient light.
I would try introducing more light slowly. From where they are growing now, move them to more light. Take a picture. Leave them in the new spot for a month.
Check your image taken now with the one you take in a month in more light, see if it improves. If it looks a bit better, try more light. Repeat the imaging process. I only suggest images to assist you in evaluating their health. Sometimes we think they are doing better, or not, but by comparing images, you may have a better idea.
See if in 2-3 months from now, they don't look better.
Also try a bit more frequent waterings. Different succulents like different levels of watering. Maybe yours will respond to more light and more water. Because now I feel that they look a bit limp and dull.