Archive files hard to distinguish from folders

### Problem

My mother is a casual computer user. She knows the basic concepts, but archive files are not one of them. She regularly needs to open downloaded archive files but she keeps thinking they are folders. The similar color of regular folders and archives makes it even hard for me to discern them at smaller sizes like 48px without looking at the file extension.

### Proposal

Changing the color of package-x-generic.svg to something that is easier to distinguish from folders. Probably white so it bears more resembly to other files like pdfs, isos and text files. Blue could be another option but I have never seen a blue package in real life. Also while blue looks pleasant, it may be a bit out of place.

### Prior Art (Optional)


Quick and dirty edits

Start by inspecting package-x-generic.svg and compare the archive icon with the supplied blue and white examples at smaller sizes such as 48px. Choose a color that makes archives easier to distinguish from folders while fitting the existing icon set; done means the updated archive icon is visibly distinct at that size.

Written by the indexing model from the issue text.