Google Inc. states:
"Color is inspired by bold color statements juxtaposed with muted environments, taking cues from contemporary architecture, road signs, pavement marking tape, and sports courts. Emphasize bold shadows and highlights. Introduce unexpected and vibrant colors."

Use this handy tool to keep the list of colours for your material designs handy. This app provides a complete set of shades of primary colours for your next app. Single tap the primary colours to view its shades and longpress any colour tile to copy its HEX code to the clipboard.