One day it would be nice to investigate some changes to popup warning and alert dialogs, including the thought of using some larger and colorful icons. I find the current icons used there are just too small and plain. They lack the impact needed to bring your attention to something important.
I have a set of larger icons on a sheet that could used for this purpose. Sample below:
Icons derived from @Andrzej Ambroz (jendrzych)'s versions. Blender logo from blender.org. Colors taken from a pallet used for highway signage.
The following zip contains the Inkscape original svg file, exported png, and py file to create such an export. Basically the three files that need to be added to the ...release\datafiles\ folder.