If you mix platinum (which I believe is white metallic gene) and a blue or I suspect, red w/blue wash) Cambodian, you'd come close. Fairly sure she's a platinum because of shiny white overlay and couple of copper spots. Cambodian because under shiny/milky white, is obviously skin colored. Her fins have only color on her and that is red and blue under the platinum.
I know how everyone hates it when I say Thai breeders so I'll just say the aquabid betta breeders that have lavender or that color purple...well a couple of the breeders give a hint at genetics and parents, like Aquastar, will say platinum red salamander or some such....