They want to be able to differentiate denominations by color (e.g. orange for tens, green for twenties, blue and red for fifties.)
Indeed they do, as they are presently all the same. I thought you said they were already different.
Maybe I'm dense, but how are BLIND people going to tell the color difference in paper money?
Also, I do believe this could be phased in, but I am totally against a federal judge legislating from ther bench and telling Congress how to conduct business.