"What" uses if you were asking what type of shoes a person is wearing like rubber shoes, high heels, formal shoes, vallet shoes etc... you use the word "what" but if you were talking about the colors then you use "which" which color of shoes, Do you usually wear... like green, black, pink, brown... Etc.... What/which color of shoes, Do you usually wear?" Both are correct it depends on what you are pertaining to.. You need to elaborate what you need? So u have specific answer. Ty
You are using the grammar of the Romance languages (Spanish, Italian, French) thus the confusion. In spanish "color de zapatos" uses an article "de" to separate the noun "zapatos" from the adjective "color". In English the process is reversed to avoid the article. Examples: "What is the...shoe (manufacturer, size, style, or color). You don't use "of".