Someone should tell the National Association for the Advancement of Colored People.

The trouble is that these terms move in and out of fashion. When I was young it would have been unacceptable to call someone "black", the respectful term was "negro", and "coloured" was also acceptable. Now it's the complete opposite. It's easy to make mistakes, particularly for older people who were brought up to use different terms, or those for whom English is a second language. The distinction between "coloured" (unacceptable) and "people of colour" (acceptable) may not be obvious.