City Hall on Thursday ordered property owners to paint, repaint or decorate their buildings within 30 days or face unspecified consequences.
In a paid notice in local dailies, acting County Secretary Leboo Ole Morintat said County Public Health Officers will visit buildings upon expiry of the notice to inspect and assess compliance by respective property owners.
County laws require property owners to repaint their premises after every two years with a view to improving the aesthetic beauty of the city and maintenance of health standards.
Last month, Governor Mike Sonko directed that all city buildings be repainted as part of a beautification exercise.
The directive was to take effect from February 1, although Sonko did not issue a deadline.
"All building should be repainted. Owners have a choice either to maintain their original colours or changing them as they please," Sonko said.
In January, Nairobi county partnered with the Rwandan High Commission to Kenya to improve the cleanliness in the city.
Rwanda High Commissioner to Kenya Ambassador James Kimonyo said that the partnership was informed by the need to replicate the steps taken by his country in keeping its environment clean here in Nairobi.
He said Rwanda was in the same state as Kenya some 14 years ago but thanks to the cleaning exercise which started in 2004, it is now green and that it was possible for Kenya to be green as well.