Yes, I am talking about in-line spinners particularly for salmon. If I understand right, white matte - it is blades that have color like Mepps or BF blades, only without luster. How B&R make them it is a secret. Matte blades - it is (IMHO) silver plated blades that not polished after plating and have grey tint.
If you rub shiny blade by wire wool or sand paper, it is also becoming matte, but it is risky: plating leer very thin and could be easy damaged.