No automatic option exists, despite its default colouration being Automatic.
depicts the configuration-window that I refer to.For lines and shapes, there is no (or, I can’t find) Automatic as default color (like it can be seen in Font Color).
My default color for shapes is Dark Blue 1.
There is no Automatic colour; the default line colour for a new document in a new installation is 3465a4
.
If you change the colour before you draw then that colour will remain as default for the current session or until you change it again. There is not a way to change the style, see Bug 89369 - Add support for drawing styles (shapes and textboxes) to Writer and Calc
I was certain that it was set to Automatic when I created the line, but indeed, the default colouration of any new shapes is #3465a4.
I’d rather like this feature. Is bugs.libreoffice.org the best place to request this?
Best to add yourself to the CC list for tdf#89369 if that is what you want implemented. Otherwise see How to Report Bugs in LibreOffice - The Document Foundation Wiki