The phrase 'The grey brand' refers to a product or service that is associated with a color scheme primarily in shades of grey. This could be a marketing strategy, a product line, or a brand identity. In marketing, using a particular color scheme can evoke certain emotions or convey a specific image, such as sophistication or modernity. 'The grey brand' might also refer to a specific brand that uses grey extensively in its branding, packaging, or advertising.