When it comes to the color "bluish-grey," there are a range of synonyms to choose from. "Slate" could be used to describe a deep, beautiful bluish-grey with hints of darker colors throughout. "Pewter" is a lighter option, with a silver sheen that catches the light. "Steel" is another word that might be used to describe a shade that leans more towards blue than grey, while "smoky" speaks to the atmospheric, dusky qualities that bluish-grey colors can evoke. Finally, "oyster" might be used to describe a more muted, subtle bluish-grey that feels calm and tranquil. These words can all be used to add nuance and color to the description of a bluish-grey hue in your writing.