documentclass[border=5mm]{standalone}

usepackage{tikz}
usetikzlibrary{calc}
usepackage{pgfplots}
pgfplotsset{compat=1.13}

newcommand{newvar}{pgfmathsetmacro}

begin{document}

begin{tikzpicture}[scale=1, transform shape]%, transparency group, blend mode = multiply]
    newvar{num}{10}
    newvar{val}{num-1}
    newvar{scale}{1}

    tikzset{
        square/.pic={
        draw[line width=1mm, pic actions]  (0, 0) -- (1, 0) -- (1, 1) -- (0, 1) -- cycle;
    }
    }
    tikzset{
        scaledc/.pic={
        foreach i in {(0, 0), (scale, 0), (0, scale), (0, 2*scale), (scale, 2*scale)}{
        draw[line width=1mm] i pic[fill=blue] {square};
        }
    }
    }

    tikzset{
    scaledd/.pic={
        foreach i in {(0, 0), (-1*scale, 0), (0, -1*scale), (0, -2*scale), (-1*scale, -2*scale)}{
        draw[line width=1mm] i pic[fill=red] {square};
        }
    }
    }

%    path (0, 0) pic {scaledd};

    tikzset{
    tile1/.pic={
        foreach i in {(A), (B), (C), (D), (E)}{
            draw i pic {square} ;
        }
    }
    }

    begin{scope}[transparency group]
    begin{scope}[blend mode = multiply]
        foreach i in {0,...,num}{
        foreach j in {0,...,val}{
            path (3*j+i, -j+3*i) pic {scaledc};
            path (3*j+i+2, -j+3*i+1) pic {scaledd};
        }
        }
    end{scope}
    end{scope}
end{tikzpicture}

end{document}