Is the caption (Friendly Name) of a Metadata field not multilangual?
Say we want to use the caption togther with the value in a given language.
Ex. Color: Red (here the value Red can be saved in each language, but how about the Name/Caption Color?)
No the Friendly Name is fixed.
If you want to make it localized, you should add translations for your properties. For example if your metafield is Color, you could have a property named Color and add translations for that property.