I used these Syn Tint dyes from http://www.bearycheap.com/ as they were the only dyes I have left. They were developed to dye synthetics but I thought I'd give them a try on silk. They did the job beautifully! 
I then covered with cling film and popped in the microwave for 40 seconds. When it came out I gave it a quick rinse in cold water and dabbed most of the moisture out with a towel. It's as simple as that! I had such fun experimenting. If you sprinkle the dye powder on the wet ribbon it gives a spotty star burst effect or if you dip the wet ribbon into one colour only and then rinse half of it before microwaving, it gives varying shades of the same colour.

If you look closely you can see the subtle colour variations within each ribbon length.

And after ironing and winding onto bobbins, here is the finished result. Of course these night time photos don't do the subtle colours justice, but you'll just have to trust me on that!

