\begin{Schunk}
\begin{Sinput}
 x <- 0:10
 y <- dpois(x, lambda=4.5)
 barplot(y, names.arg=x, col=c(rep(gray(0.95),3),rep(gray(0.70),1),rep(gray(0.95),10)), space=0)
\end{Sinput}
\end{Schunk}
