As far as ridicule based on looks, I don't think anyone should ever be ridiculed for a choice of personal style, REGARDLESS of what style it is. I think there are limits to what is acceptable in certain situations, but still ridicule is not a good tool for change.
As far as the 'goth at work' thing...Your employer likely implements a dress code to display professionalism. The fact that you don't have to wear a uniform is already a step more lenient than many businesses. What you should do is get a written copy of the dress code and check it over to see what does and doesn't conform to policy. If there is nothing in the dress code specifying that what you are wearing is not allowed, you can mention to your employer that your outfit does fit the dress code and if you are pressed mention it would amount to discrimination if you were forced to adhere to a stricter dress code than your co-workers.