  A vertex $v$ of a given graph is said to be in a rainbow neighbourhood of $G$
if every colour class of $G$ consists of at least one vertex from the closed
neighbourhood $N[v]$. A maximal proper colouring of a graph $G$ is a Johan
colouring if and only if every vertex of $G$ belongs to a rainbow neighbourhood
of $G$. In general all graphs need not have a Johan colouring, even though they
admit a chromatic colouring. In this paper, we characterise graphs which admit
a Johan colouring. We also discuss some preliminary results in respect of
certain graph operations which admit a Johan colouring under certain
conditions.
