I tried colouring the beads with colour sprays which did work but didn't give me the density of colour I was looking for. The pink and green beads are coloured with the sprays. I used acrylic paint for the blue and green beads and some silver rub'n'buff to bring out the patterns. I used coloured metallic rub-ons for the other beads (the clay was white) and I like the look of these but I don't know how long it will take for the metallic rubons to dry (if ever). If it doesn't dry I may have to coat them with varnish.
Update: The metallic rubons didn't really dry so I put some UTEE onto them and it stuck to the coloured pattern. Heated and it gave a glassy finish to the beads too.