But while some institutions have already adopted the changes, a majority of public schools are yet to adhere to the regulations.
The directive by the CS borrows from institutions in the United States and Canada that have their school buses and vans painted yellow. A similar proposal has been mooted in the United Kingdom.
And in a raft of measures by the ministry, aimed at streamlining the education sector ahead of the rollout of the new curriculum.
The Cabinet secretary also cautioned principals of day secondary schools against charging parents extra levies, against the recommended fee guidelines issued by the government.
The proposals by the ministry also seek to give regional and county commissioners the responsibilities to chair county education boards.