I disagree with the premise of avoiding releasing ethnicity and skin color information. At times, this information is vital in identifying a suspect. Keeping the general public safe is a larger concern than the threat of possible racism. Apprehending a suspect as soon as possible keeps everyone of all races safer.
Filing information about suspects is crucial to detective work, and in no way "puts the general public in danger." If a suspect has brown skin, and later on a crime is committed by a white person that the police believe to be guilty of the crimes investigated, then the police can know to dismiss the other person as a suspect. Likewise, if it turns out the white person isn't guilty of all the crimes, they can return to their filed work and try to pursue different clues.
I think it is not putting the general public in danger to withhold certain aspects of investigations or suspects of investigations. It seems to be put in place to suppress the basic racism that some people have when reporting crimes, so without influencing their story, they can talk about certain suspects without racism in the picture.
It's one thing is you have a good picture of suspect, yes that should be circulated. But just telling people that a black man is robbing people only makes already racist people start to judge every black man they meet and fear he is a criminal. Nobody is put at risk when they don't have that information.