Yes, you are right. It is called grafting. But I would go for T chip budding.
Colour of root stock has no effect on grafting. Grafting allows you to select a root system adapted to your climate and soil, or resistant to local pests and diseases. Nurseries use standard rootstocks for grafting, but you may try on any rose bush. Selecting a naturally growing species rose in your area as rootstock would be a good idea