I asked someone online what kind of paints they use for their custom model recolors and they identified this product:
https://www.behr.com/consumer/produc...el-spray-paint
But I don't think they offer this for sale in Australia.

So does anyone know what is the local equivalent I could purchase is?

I don't need very much, so smaller quantities would be desired.
About as much as is needed to paint half a Combiner Wars limb.