Personally I would chainsaw the pygmies. They are too thorny and drop a lot of seed. Yours do not look well tended. Do you water? "Stunning colorful look" is not so easy in a low-water environment. I suggest succulents such as Euphorbia tirucalli, Echeveria -- various colors, Kalanchoe luciae or thyrsiflora, Aeonium zwartkopf, other various colors, Senecio mandraliscae, and so on. Go for Aloes in the larger sizes, maybe some Kniphofia. These plants are not fast growers, they take some time to fill in, but you will not get a lot of litter from them, a big plus around a pool. They look most colorful in winter, and retain a good look all year round. They need water to establish, but after that, don't need much.

Plant in groups, taller plants toward the back of a planter or in the middle of a round planter, for example. If you plant 5 of one kind of Echeveria it will be more effective than "one of this and one of that."

I don't know how realistic it is to expect these beds to be "colorful." Mainly, they just need to have something solidly growing in them so they are some version of green instead of brown or grey. Water, as mentioned by Kiminpl will be necessary. And weeds cannot be allowed. Color could be limited to the places where it grow well and is easiest to maintain.