I echo what the above posters said. There's a couple health systems where I am at and one uses the one color for each role and the other doesn't. The one that uses the one color still doesn't distinguish the role.
1) Like the other poster said, everyone else knows who is who except the patient; plus, some patients are so sick, that they don't care what color you wear or do not want another thing to have to memorize/think about.
2) Sometimes the roles have such close colors that after a couple of washes of the scrubs
, it becomes ambiguous.
3) Think about the patients that have poor eye sight or are color blind.
4) What's wrong with the good ol' fashioned "Hi, I'm Jane/John Doe, I am going to be your nurse today"? or having tags on the badges that tell your role.
Just doesn't work. Plus, I would rather pay less money for a plainer hospital and have the staff in "pretty scrubs" than pay more for a "pretty hospital" and one color scrub providers. My point is, typically, the hospitals that do the all one color thing have the pretty art, etc. in their hospitals; but the cost is passed on to the patient. The "pretty scrubs" are paid for by the employee.