Here is a nice little trick I found on a web forum about how you can get free coloured gel filters for you Canon (and probably other brands) flashguns.
The idea is to order free color filter guide book from Rosco that gives you a whole selection of colours to choose from.
You can order the book from Rosco UK, or Rosco US
The trick lies in that these are a perfect size to fit over your flashgun head 🙂
The book looks like this
All you still have to do is to unbind the book and use your imagination to fix the gel in front of you Canon Speedlight flashgun
At the end it should look something like
Simple but ingenious idea 🙂
The idea comes from stupot and originaly posted here
I also read today on DSLR Blog, that it is also possible to get free coloured gel for the flashgun from Lee Filter, all you will have to do is check their filters list, then order a swatch book using the online contact form.
Hope it helps