Brand Colours (Colour Palette)
Brand colours are a company's defined colour palette, usually a primary colour, one or two secondary colours, an accent colour for actions, and a graded set of neutrals. To look the same everywhere, each colour is specified as concrete values per medium: screen, print and signage.
In practice
A palette with two strong colours and plenty of greys carries further than seven equally weighted hues; too many colours cancel each other out. Plan the accent colour for buttons from the start and never use it decoratively, otherwise the most important click loses its pull. Check every text-on-background combination for sufficient contrast before the palette is signed off, because later corrections ripple through every template. Allow for a dark mode as well, since many users have it enabled system-wide. Keep the values in one central place, ideally as design tokens.