My mum has got coloured, patterned concrete. Makes it look as if you have individual slabs down.
It was done about 20yrs ago. No idea of cost, but I remember it being VERY messy. They laid the concrete, then they put the coloured powder on. It got everywhere!
But to be fair, bar the odd power hose every few years, and the odd sealing every 10yrs or so, it still looks good.
Google for patterned concrete, then go to Images, you'll see plenty of examples.