My biggest advice would be to NOT buy a delta printer if you want any sort of quality output. Whilst delta printers (like the one in your picture) are faster than i3 or cartesian printers they lack the stability of any other type of 3d printer and so cannot compete when it comes to quality.
You can get a cheap 3d printer kit for around £150 fully complete (a build it yourself kit) and then add the parts to make it multi colour. Something like the Anet a6, a8 or a10, all very good printers and cheap. You can get any number of cheap Prusa i3 clones ether as kits or pre-built and then add a multi colour kit to those.
There are an absolute ton of 3d printer vids on youtube I would watch a good few before buying a printer, you will get a much more wide and varied set of reviews. I would recommend 3D Printer Nerd, Makers Muse, 3D Printing Noob, Thomas Sanladerer, they all have good reviews of many printers including cheap and expensive kits as well as multi colour 3d printing.
As it stands at the moment printing multi coloured object is more of a bind than useful and unless you spend mega bucks on a printer that handles it well you'll be ripping your hair out in no time.
Personally I went the other way and started off with a dual nozzle (2 colour) printer and turned it into a single colour printer because of issues getting both nozzles right. But multi colour through 1 nozzle is better in that respect but you have multiple other issues, like if you use different brands of filament they will be set to melt at different temperatures and there may be a lot of heating up/cooling down time with a single hotend, there is a lot of waste as each time you change colour you have to purge the previous one. The 3 extruders have to be set to the correct speeds for the filament they are using or you'll get under/over extrusion.
