I just had an idea which might be pretty useful from a programming perspective.
If you press a keyboard shortcut, it would bring up a browse dialog box from which you can select a file or folder, and then it would insert at the cursor the relative path of what you selected.
The same could apply to color pickers, where it would bring up a colorpicker for you to select a color and it would paste where your cursor is.
I just hate having to go to another app to find the color I need or open a file explorer or command prompt to find the path I need to paste into the editor. I think these are general enough to be included in an editor, especially the browse file dialog box.