I take your general point. But this is increasingly becoming an outdated limitation, along with ideas such as professionals don’t have tattoos or facial hair. Some industries are more conservative than others but even when I was in banking some eccentricity was accepted as long as the person delivered the goods. Sure if you’re in a setting that puts a lot of stress on conformity you want to be conscious of it but IMO that’s less the rule these days.You don't drive your car into a business meeting though, do you?
Nothing wrong with having a device that a fancy colour of course. Just looks out of place in a professional environment.