What kind of noise is city noise? White, pink, brown...? In general, to what category does it subscribe the spectrum of city noises, like traffic noise, ambulance/police siren, alarms, etc, put together?

If the question is too broad, then, what is the color for particular noises, like traffic?
Noise color isn't a rigorous model for traffic noise

https://hal.archives-ouvertes.fr/file/index/docid/506615/filename/Can_2010_Applied_acoustic_71_8_p.pdf