For added coloured fuzziness, here’s how to achieve them!
Using Photoshop i created some different shaped rainbow coloured gradients and some black and white ones (although I’m forgetting about those as they didn’t work, haha!) and then printed them on to some inkjet acetate (use whichever acetate suits your printer, laser, etc.) I then blu-tacked them to the front of my lens and went out and shot some pictures. using these filters can make focusing on an SLR hard so I suggest you do it before hand then sticking the filter on after, as for me im to lazy and just guessed.
I was a little disappointed when I first got the shots back but after a while they kind of grow on you with there colourful dream like looks, I found the colours show up a lot better on paler colours and it helps to overexpose the shots a little to make up for the filter. I’m sure this tip could be worked on a little to make the shots a bit better but is a good basis to get you going :)
Just don’t forget to bracket your exposure since you’re using these as filters.