I stuck to Pam's suggestion of working a differing weight of filling for each section, but didn't use my variegated thread in the end, it was a little too thick and would have looked unbalanced against the outline. I did use red though, which is always the first colour one thinks of with roses and this is a sort of rose. I've used two closely allied reds to reflect the way the colour of rose petals is sometimes shaded from centre to tip. I'm really happy with the result though, no, I'm NOT going to show you the back!
Hope you like it.