As an adult, I want a brightly colored hearing aid. I don't care about hiding my disability—in fact I'd rather it be difficult for others to ignore—and I want it to be easy to find if my kids knock one out of my ears which happens less now that they're six but still happens.
Indeed, to make an even more direct comparison: brightly coloured glasses are very common these days. They seem to be treated like neckties: it's acceptable for them to standout even in very formal situations.
I didn’t mean it to be about ‘hiding’ your disability. I wear glasses and I would never wear brightly coloured rims in a professional environment. By my own standards, in a work place you stand out by the merits of your work, not on what you’re wearing.
This is your opinion. In many parts of the world, criticizing a piece of accessibility equipment as unprofessional is likely an HR violation, and probably grounds for termination.
It is and you are correct.
It’s not unreasonable for someone to want a more neutral colour if that is their preference though. Some HA users are self conscious and hide that they are wearing them.