This is a permanent pro product which you can get for the Mac website or one of their pro stores (I think I picked mine up from the Carnaby Street branch).
It is a:
'Versatile and multi-purpose, Cream Colour Base can be applied directly to bare skin, or layered over foundation, moisturizer, or powder. Smooth and easy to apply with a brush, sponge, or fingers-colour effects range from a light veil to highly dramatic, depending on method of application.'
I remember going with my cousin to the store, and we pottered around, swatching and giving ourselves a quick make over with the products. She picked up a whole bunch of things and I got jealous so started looking to see if there was anything I could use that I haven't already got. It was the colour in 'Madly Magenta' that initially caught my eye. But they didn't have a fresh one in stock, so I made-do with the 'Pink Shock'. And I haven't regretted it.
The texture is really creamy blends on really well on the cheek. It's fine on the eyelids as a base but what I use it most for are the cheeks and lips. Considering the intensity of the colour, you'd think its something to wear on a party night. But I actually use it quite a lot in the day time. You just need to pick up a tiny amount on the brush (I use the 116 mac blush brush) and it blends out really well giving a doll-like effect on the cheeks. I also apply a small amount on the lips with a brush and I feel that it gives me an instant youthful pick-me-up. Although I do need to wear a lip gloss over it because it is a tad too drying for me after a little while. I love the way you can build the colour to make it subtle or completely dramatic. This is actually what I wore a lot in autumn to work and it wasn't too much and I honestly reach for it quite often.
I love, love this and considering that it is multi purpose, its worth the money.
One thing I should mention is that not all the cream colour bases are multi purpose. For example, some are not suitable for the eye or lip area. So make sure you ask at the store and read up on what you can use each colour for. I think it cost me about £12.