drawing area (purple box)

I’m trying to draw through this purple box but I cant. I’ve never noticed this purple box area of drawing, how can I deactivate this purple box?

Screenshot_2.jpg

This limitation is called the “Default Canvas Size for Bitmap Layers” and is designed to
let you work in a way that won’t burn through all the system resources by limiting the
size to 200% of the project resolution. The thing to note is that every time you double
the size of a bitmap image, it uses up four times as much memory.

This is set in the Drawing tab of the preferences for projects as a whole.
To change it in the current projects for layers yet to be created:
Menu-Scene-Scene Settings on the “Bitmap Resolution” tab.
To change it for the currently selected layer only:
Camera Window’s menu-View-Bitmap File Quality

One way to draw larger (or with more detail) is to simply zoom-in on the layer where
the actual bitmap resolution is not actually needed to be enlarged. Keep in mind also
that you can “scale” the drawing to appear larger on the layer’s (or parent peg’s)
“Transformation” tab