To the best of my knowledge ribbontail is the expression of bronze on an Ash Red base. I don't remember where I got that information, and I don't seem to have a link saved for the information. It may have come from some of the old pigeon books I had. The phenotype that shows a whitish ribbontail like in Lebanons may be different then the genetics for the grayish ribbontail in rollers and tumblers. I know that bronze combined with Ash Red is responsible for ribbontails in rollers. I have bred a lot of them.
You might be able to find something on the net using a search for bronze phenotypes.