Well, after looking at the pic, the pink one is likely toast. You may have a chance at rooting the yellow/orange one by cutting it off half way between the rot and the yellow (cheating closer to the yellow) let it callous over and then try and root it. If you try this with the pink one, do it in a separate pot. The soil you have them in looks quite heavy, what is it? tj

What you had was a mutant Gymnocalycium mihanovichii, cultivar 'Hibotan'. It has no green chlorophyll, so other pigments are visible, causing the red color. It has no way to feed itself, so it is grafted onto rooted stock, typically a Hylocereus. The 'ruby ball' cannot survive on its own. Since it has rotted, all you are left with is the relatively uninteresting root stock. Gymnocalycium mihanovichii cv. 'Hibotan'

That looks like a large terracotta pot. It might have a drainage hole. However, it looks too big and I can't see the kind of soil in it. I'm guessing that isn't a pot full of quartz sand. However, if it is a large pot full of quartz sand then I can see how that might be difficult to correctly water to keep the plants healthy. The two spiky plants in the back look like Hoodia. They are Asclepiads rather than Cacti. They look unbothered about anything. The front left plant might be a dark-leaf Aeonium. However, I'm not sure the stem should be that dark. The stem might be rotten. The center red ball cactus was grafted on to a root stock and the root stock died. Unfortunately the red ball cactus can't be saved without grafting it on to another root stock. The dead root stock is a common problem with that plant. I agree the P. afra in the back right and Echeveria in the front right look like they can be saved. You might have to cut the long stem off the Echeveria and reroot the top. If those were mine I'd prefer to plant each one in separate smaller pots. Group plantings in a pot bought at a store often don't work long term. In this case the plants might look like they need to be watered but have been watered too much, or been moist too long, and lost the healthy functioning of their roots. Without healthy roots plants can look like they need water even when the soil is moist. Some people asked if the dish was purchased "as is". I'm guessing they meant to ask if it was purchased as a group of plants in one pot rather than ask if it was sold marked as is meaning no guarantee the plants were healthy. If they were sold with no guarantee then I wouldn't bother trying to return them. Sometimes I buy plants like that.

Ycloh1, I'm afraid I've managed to damage a Crassula Buddhas Temple that I recently acquired. It was a cutting that had very small root nubs beginning when I got it. I potted it up and it was initially doing well but when I looked the other day, one side of it was dried out looking. I think what may have happened is that even though it was on my table under the umbrella, as the seasons change from Summer to Fall, the sun's position in the sky is changing so that where once the sun was more overhead, it is now at more of an angle so the umbrella is offering less protection. The sun is hitting from the side. I think my Buddhas Temlle got direct sunlight at the peak time of the day and was burned. Anyway, I unpotted it and there appear to be no living roots. Some of the fine roots that formed appear to be dead. Have you tried this water culture method on any Crassula? I'm not sure whether I should just clean it up of the apparently dead roots and remove some of the lower leaves and set aside to callous and form new roots or whether I should try this water culture method. Thank you for any advice offered. Tyler