\documentclass{standalone}

\usepackage{tikz}
\usepackage{shapes}

\begin{document}
\begin{tikzpicture}
  \grid{6}{6}{(-2,-2)}

  \square{qualitative4-2}{(0,-1)}
  \square{qualitative4-2}{(1,-1)}
  \square{qualitative4-2}{(2,-1)}

  \square{qualitative4-3}{(-1,0)}
  \square{qualitative4-3}{(-1,1)}
  \square{qualitative4-3}{(-1,2)}

  \square{qualitative4-4}{(1,2)}
  \square{qualitative4-4}{(2,1)}

  \square{lightgray}{(0,3)}
  \square{lightgray}{(3,0)}
  
  \staircase{qualitative4-1}{(0,0)}
  
\end{tikzpicture}
\end{document}