Mozilla Firefox and their irritating grey folders

I use Firefox because years ago I decided not everything from Microsoft was magic. Their complete and utter monopoly of the internet and my own machines is annoying and incredibly irritating. Changing from Explorer to Firefox was not just an act of rebellion it was an act for the little man and little woman. Why should companies like the big M and google have access to all our data and know everything about us? I've even heard Facebook listens to conversations and then tailors adverts to your news feed. Apparently in testing this a user talked about cat food all day long even though they had no cat. Only to find their news feed was full of adverts for cat food. I might try this myself and see if it is true. However, now Firefox has gone the way of making an assumption about it's users and not engaging with them, it's updated to yet another version to increase speed however it has now made the drop down bookmark folers turn a boring and difficult to see grey colour.

So there is now the option of going to Chrome or trying to find a solution. This single act of changing the folder colour from yellow to grey has pissed me off. But I'm only a little fellow so Firefox probably doesn't care about the opinio of a little fellow. Yet in doing so it may find it loses it's users. I look for work arounds and check the settings to see if there is some option to change the dull flat grey back to the yellow I liked and used to see. There's nothing. I've checked a web site which has an option to load a segment of code into some part of firefox in order to change the folder colours. But this seems drastic to me and seeing as I can't read code or understand what it will do I'm apprehensive. Like the old saying, if it aint broken don't fix it. So the question is firefox why the fuck did you piss about with this small part of the interface and fuck it up?