The Preferences Panel allow to change some global setting in Plot

Open Initial Empty Document: If checked Plot starts with an empty document.

Hide Document Toolbar: If check the document title bar has no toolbar.

Default Time Format: Set the default format for time values used in Plot.

Default Fonts: Set the default fonts for axis labels and axis numbers.

Set Default Style: If clicked the style of the current working buffer in the current document will be the default style for new data buffers.

Reset Default Style: Reset the default style for new data buffers.

Default Colors: Here you can define your own default colors used by Plot. It is also possible to restore the default colors provided by Plot.

Default Colors: Defines a global storage location for macros and MySQL import (e.g. Dropbox).

Default Import Options for Copy & Paste: These options apply only for data imports made with copy and paste or drag and drop.