Steel-gray is a color that is often associated with industrial and mechanical materials. However, if you're looking for synonyms for steel-gray, there are plenty of options to choose from. Some of the most common synonyms for steel-gray include gunmetal, silver-gray, slate, charcoal, and ash. These colors are often bold and sophisticated, making them ideal for interior design and fashion. Other possible synonyms for steel-gray include pewter, leaden, and anthracite. Each of these colors has their own unique properties and can be used to create a range of different looks and styles. Ultimately, the best synonym for steel-gray will depend on your personal preferences and the context in which the color will be used.