I use different coloured copies of the default folder icon to indicate certain types of folder, like “Urgent” and “Past Urgent”.
So just recolouring the default folder, the icon itself stays the same.
I store these folder icons in /Pictures/Icons
I tried in a dot file location but hiding/rehiding when poking about locating them is a faff.
I’ve been aquiring the knowledge to use python-nautilus to make a context menu where I can choose the folder colour, to make it quick and easy.
For me, changing the folder colour is a hack to try and get back some of the usefulness of the old MacOS Finder tags. It would be nice to also add tags, and search and sort by them.
I find using bitmaps on folders makes it too easy to confuse them with normal image files in the grid view, as I’m used to OS where files hide their extensions.
I don’t use custom icons on normal files, as in grid view most of them have thumbnails, apart from text files. Text file thumbnails would be a blessing.
That makes me remember that there are a few PDFs I’ve wanted to change the generated thumbnail icon on in the past, because the default one is blank or non-descriptive, but havn’t because I didn’t have a process to create a thumbnail and then keep the two in sync.
Cheers.