Melocactus azureus Cactus Care is more similar to

Care is more similar to a succulent too

They tend to be green when growing and pink when dormant

Sansevieria kirkii 'Silver Blue'  A very attractive upright Snake Plant or Mother in Law Tongue with thick silvery blue green leaves

They are probably E

To get the degree of pink seen in the first image you probably need to keep it on the dry side as a bit of drought stress brings out the most stunning color

Melocactus azureus Cactus Care is more similar toMelocactus azureus Family: Cactaceae. This is a nice cephallium forming cactus with blue to blue green skin. It looks and grows like a normal cactus for several years but once it gets big enough the main plant stops growing but produces a large hairy inflorescence that continues to grow for the rest of the life of the plant. Eventually the inflorescence can be taller than the plant itself. This is more tropical than most cacti so it doesn't like cold