Can someone explain to me the reason why on L.C. Smith ejector guns the forend iron is case colored. On L.C. Smith extractor guns, the forend iron is blued. Other than the answer, "this is how they did it", can someone explain to me if there is an actual reason?

Is it that the extra cost of having ejectors also inclued the cost of having the forend iron case colored? The lower cost extractors got a simple blue job? Just curious...