bright dip/anodizing will/could vary between the same and or different vendors, which is why it's usually wise to maintain the same vendor, and have all the pieces done in one batch/lot

Same goes for chrome plating, shop A might use a smoke/grey chrome finish, and shop B uses blue chrome finish, some will ask/tell you, some just take the parts and finish them to what's in use/shop SOP/etc, both shops work appears like "bright chrome", till you combine/match components that you had each shop do for the same project, same happens with bright dip/anodizing, black oxide/ cad plating/etc/etc...and going back to the same shop months or years later is no guarantee that parts done long ago will match parts to be done/redone