past posting on permitted colours

Don't know about your area but in our area you have to apply for permission to change the colour of the external walls of your house. That is probably why you were invited to open a dossier by your local Mairie. In fact it is the Dept D'urbanism (or something like that) which looks after all this stuff. You have to produce pictures/drawings of each elevation showing the house as it is now and what it will look like after it has been painted. They do not supply crayons though.

We just gave up and are painting it anyway, just as all our French neighbours do!.