Did look for that Carb but could find it - likely gave it to someone that could use it. I do recall these brackets being zinc dichromate from recall.
As always with zinc dichromate the yellow/gold color does not last as long as the underlaying zinc and can often be thin/washed out. Originally it was more of a wash/dye job and its not unusual for current platters to apply it with a heavier hand IMHO
Just adding couple of pictures to illustrate the items being discussed and how age can affect finishes. Also the location and how much expose it got over the years can affect the life of the wash/dye also. In some below we can make out other dichromated parts elsewhere on the carbs
Remember lighting, contrast and camera settings can effect what you are seeing in the pictures