Eve of Milady

Does anyone know if they allow their dresses to be customized from the manufacturer??? (Example, changing the color of the embroidery work) One salon told me no and if by chance you asked them to do it, you would be paying big $$$$$. Another place told me it's no problem. All these bridal gown sales people are beginning to sound like used car salesmen to me....anyone have some real info??? I'd appreciate it.