Thus if the normal colour of a note (attribute $Color) is 'warm gray dark', and a prototype then has its
$Color altered to 'green' then the notes using that prototype will inherit that change whereas other notes will not. This is true for any attribute, System or User, that can be altered by the user—i.e. all except read-only attributes.
Also notice that compared to the previous step's image, when
$Color is displayed as a Key Attribute, the name and value were shown in normal weight font but are now in bold. This is a deliberate tell-tale. Bold text indicates that this particular attribute in this particular note is set 'locally' (or immediately'). Local values always override defaults.
The same normal/bold hinting is used in both Key Attribute tables in notes (as seen above) as well as in the attribute tables used in the Get Info dialog. One other styling used in these tables is a light grey text for attributes that are read-only, and which can't be edited.
Now to see how prototype alter the cascade from higher levels…