The ERASE procedure erases the screen of the currently selected graphics device (or starts a new page if the device is a printer). The device is reset to alphanumeric mode if it has such a mode (e.g., Tektronix terminals).
The color index for the screen to be erased to. If this argument is omitted ERASE resets the screen to the default background color (normally 0), stored in the system variable !P.BACKGROUND. Providing a value for Background_Color overrides the default.