I've used mystic fog twice in my system. One from concentrate and more recently the premix. Both have been extremely disappointing, I see very little of the rgb goodness you see in the promo images and it's definitely not UV reactive.
The premix actually went clear after 2 days, I couldn't see any deposits in the fins of the heatsinks so I added a few drops of Mayhems UV green. At least it's UV reactive now.
I would avoid mystic fog personally, it's not mystic, it just looks like semen flowing through your pipes!
Regarding UV I use some UV led lights powered from USB. They have 3M tape which sticks well, a 2 pack cost 13 quid from the usual place. One reel goes round the front window my 5000x nicely.