While multi-coloured hair, tattoos and piercings are becoming increasingly mainstream, many people still feel such physical enhancements are inappropriate in the workplace.

But is it really right for a stranger to pre-judge your professional abilities because of the colour of your hair?

West Virginian nurse Mary Walls Penney felt compelled to answer this very question over the weekend when her rainbow coloured hair left a cashier wondering how she could possibly be allowed work in a medical environment.

In a Facebook post which has since been shared over 100,000 times, the young mother explained how her hair caught the attention of a store worker while she was out getting groceries.

She wrote: "While checking out, the cashier, looked at my name tag and said, 'So what do you do there?' I replied, 'I'm a nurse.'"

"She continued, 'I'm surprised they let you work there like that.  What do your patients think about your hair?'"

"She then proceeded to ask the elderly lady that was in line behind me, 'What do you think about her hair?'" 
The kind older lady said, 'Nothing against you honey, it's just not for me.'"

"Then the cashier continued to comment that they didn't allow that sort of thing even when she worked fast food and that she was shocked that a nursing facility would allow that."

After setting up the context for her argument, Mary went on to explain how her physical appearance has never interfered with her ability to perform at work.

She said: "I can't recall a time that my hair colour has prevented me from providing life saving treatment to one of my patients."

"My tattoos have never kept them from holding my hand and as they lay frightened and crying because Alzheimer's has stolen their mind."

"My multiple ear piercings have never interfered with me hearing them reminisce about their better days or listening to them as they express their last wishes."

"My tongue piercing has never kept me from speaking words of encouragement to a newly diagnosed patient or from comforting a family that is grieving."

"So, please explain to me how my appearance, while being paired with my cheerful disposition, servant's heart, and smiling face, has made me unfit to provide nursing care and unable to do my job!"

Mary's emotive post has received a positive reaction online with some Facebook users saying they would love to have her as their nurse, while others shared their own experiences of having strikingly coloured hair.