If I may, I find some succulents are more likely to get mealies than others. I've also found when the plant is watered, they tend to end up as far away from moist soil as they can get. Near the tip of the stems which makes it easy to use rubbing alcohol on a Qtip. It is fun to hear them scream in agony.
I have had root mealies in some succulent pots in the past. For that I drenched with a dilute solution of Bayer Advanced Tree and Shrub. (BATS) It was either that or toss a bunch of plants.
I'm not sure about the yellowing but if you meant the C, gollum, I would say it is due to the time of year. Both colder temps and shorter days will cause succulents to change in color. If it is needing water, you will notice the bottom growth shrivel and drop off.
In order to not wet the plant, you can water from beneath by setting the pot in a shallow pan of water. Just don't forget and leave it standing in water.
I agree with Tarev, when it is cold, succulents need very little water or attention. That is part of their charm.
