\documentclass[12pt]{standalone}
\pagestyle{empty}
\usepackage{tikz}
\definecolor{darkblue}{rgb}{0,0,.7}
\begin{document}

\begin{tikzpicture}
\begin{scope}
\clip (-2,-1) rectangle (8.5,4);
\fill[yellow] (-1,0)--(2,3)--(8,0);
\foreach \x in {-4,-3,-2,-1,0,1,2,3,4,5,6,7, 8} \draw [red] (\x,0)--(\x+3,3);
\foreach \x in {-4,-3,-2,-1,0,1,2,3,4,5,6,7, 8} \draw [cyan] (\x,0)--(\x-3,3);
\foreach \x in {-4,-3,-2,-1,0,1,2,3,4,5,6,7, 8} \draw [blue] (\x+3,0)--(\x-3,3);

\fill (2,3) circle (.04) node[above] {$P$};
\node at (3,1) {\colorbox{white}{$\Delta(P)$}};
\end{scope}
\draw[very thick,->] (-2,0)--(8.5,0) node[below] {$x$};

\end{tikzpicture}
\end{document}
