Grey-collar refers to professions where the nature of the work cannot easily be classified as blue-collar or white-collar. As such, the category represents an intermediary between blue-collar and white-collar work that combines elements of both categories in regard to the nature of the work and the required type of training, licensure, and formal education. In general, the category requires more intellectual labor than would be required of a blue-collar profession and more physical labor than would be required of a white-collar profession. The concept helps address, but does not fully resolve, classist attitudes towards and misconceptions about different professions.
The concept is more loosely defined than the dichotomy of blue- vs white- collar, and is therefore somewhat controversial. Grey-collar may be interpreted as a spectrum between the two extremes of blue- and white- collar. Due to the open-ended nature of the concept and the issues with treating blue- and white- collar as a rigid binary, a wide range of professions may be considered grey-collar. As such, definitions of the category may differ across contexts and in individual interpretation.