grid_RBG+3d+foreach+learn.tex

% https://tex.stackexchange.com/a/271584/173708
\documentclass[border={10}]{standalone}
\usepackage{tikz}  
\usepackage{tikz-3dplot} 

\tdplotsetmaincoords{60}{125} % view angles
\tdplotsetrotatedcoords{0}{0}{0} 
\begin{document}

\begin{tikzpicture}
    [%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        scale=5,tdplot_rotated_coords,
        grid/.style={very thin,gray}
    ]%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

    %draw a grid in the x-y plane
    \foreach \x in {0,1,...,10}
        \foreach \y in {0,1,...,10}
        {
            \draw[grid] (\x,0) -- (\x,10);
            \draw[grid] (0,\y) -- (10,\y);
        };
    \draw[fill=blue]  (0,0,0) -- (0,1,0) -- (1,1,0) -- (1,0,0) -- cycle;
    \draw[fill=red ]  (1,1,0) -- (2,1,0) -- (2,2,0) -- (1,2,0) -- cycle;
\end{tikzpicture}    
\end{document}