What's the plural form of gunmetal gray? Here's the word you're looking for.
Answer
The noun gunmetal gray can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be gunmetal gray.
However, in more specific contexts, the plural form can also be gunmetal grays e.g. in reference to various types of gunmetal grays
or a collection of gunmetal grays.