Warning symbols can be displayed on colour chips to inform the user of the following: whether the colour is close or out of monitor or printer gamut; if the colour has an individual transparency; if the colour has a resist value set; whether the colour is exempt from colour file updates within a design and whether the layer itself is enabled as a spot printing layer. 

Symbols left to right: Monitor, Printer, Transparency, Colour file updates, Resist, Spot printing

Switching on the warning symbols to appear on colour chips in AVA

Go to AVA Menu > Inspector > Warnings… and tick Gamut Warnings on Colour Blocks. 

Switching on the gamut warnings on colour chips in ColourSys

In ColourSys, go to View Menu > View Settings. Change the Chip Layout from List to any other format, and tick Gamut Warnings.