Hi Ivanhoe,
I undercoat with either Humbrol matt enamels or Jo Sonja Acrylics. I almost always overpaint with artist oils. I use W&N, Rembrandt and Old Holland brands.
Lavender was Old Holland. Only Titanium white gives you the most intense white colour. I use zinc white with lavender to give an off-white look.
The iridescent colours were developed mainly for acrylics, giving a nice shiny "pearl" look. W&N had an iridescent white colour which I used. This is not opaque and the end result is a glaze.
I've painted the face and skin, reattached the rose, and painted the hair and other details.