\documentclass{article}
\usepackage{l3draw}
\begin{document}
\ExplSyntaxOn
\draw_begin:
\draw_color:n {red}
\draw_color_fill:n{red!50}
\draw_path_rectangle:nn
{ 1cm , 0cm }
{ 1.5cm , 1cm }
\draw_path_use_clear:n { fill, draw }
\draw_color_fill:n{blue!50}
\draw_color_stroke:n{blue}
\draw_path_rectangle:nn
{ 1.5cm , 0.25cm }
{ 1.5cm , 1cm }
\draw_path_use_clear:n { fill, draw }
\draw_color:n{green!50}
\draw_path_rectangle:nn
{ 2cm , 0.5cm }
{ 1.5cm , 1cm }
\draw_path_use_clear:n { fill, draw }
\draw_end: