No Purple.. the only thing on the game page that means play later, is "Play Later".
The only place that mentions "default" is as Bwildman described. It is where you can choose something different than "go to main page" as the destination after submitting your move. (You can make the "default" go to next game with online player, everytime you submit, without changing it from go to main page each time..

Definition of default relevent to this:
"Computer Science. A particular setting or value for a variable that is assigned automatically by an operating system and remains in effect unless canceled or overridden by the operator: changed the default for the font in the word processing program.
A situation or condition that obtains in the absence of active intervention.