Don’t see any problematic messages with “ usual “ buttons. Those look bronze, though— I like bronze and similar toned- down metals, and have handbags with warm dark- toned metals because cooler tones were harder to find, but since my color palette has gravitated to cooler colors and silver jewelry, I have tried to focus on pewters and such. But, I also don’t think it’s horrors to mix metals.
I’m going into such details because good metal coat buttons can be pricey (because are usually larger , especially if lots of buttons- sleeves, detailing) even though much cheaper than a new coat, so you want to really like the coat and be thinking about changes that not only fit the essence of the coat but also make it work better with your current wardrobe.
I recently changed buttons on a blazer from silver , though some kind of faux metal, to navy plastic because I avoided wearing shiny metal buttons ( the ones you’ve shown are not shiny- this is just my example) and could not find just the right kind of dark real metal in the sizes needed, plus was not 100% sure yet, in pandemic, how much I would wear it.
But, it’s a good economical way to change up a garment otherwise.
