Welcome to this forum, Pepper.
You do seem to like Sempervivums! In regards to your question, Sempervivums do change their colors as the seasons go by. In Spring they tend to be their most vibrant in color and then they tend to turn different colors of green. This is why Spring is the best time to buy Semps as one can see the differences. Also for some cultivars, the sun will heighten the coloring while in other cultivars, the cold will do that.
If your semps "feel great" like how they were when you bought them, then it sounds ok. Your first photo shows 3 pots and the one on the right looks like the rosettes are stretching (etiolating) for more light. This is a result of them not having enough sunlight. Eventually the rosettes will lose their compactness/shape as the leaves of the head stretch out. Ideally Semps should be outside to get the sun exposure and the ventilation. They are hardy to very cold temps as they are alpine plants.
Your last photo shows an Echeveria, not a Semp. That is a tender succulent and is not hardy. It can be tolerant to 7 C (45 F) in temperature. Your plant can be indoors but needs to be near window w/ full sun to maintain the compactness of the rosette shape. It should not change in color though it may fade a little because lack of light.
