Suset codes in venndiagram package

Question

Looking for ways of doing the following:

1. Drawing set A inside set B;
2. Coloring different sets differently.

Answer 1

A simple code for the question.

\documentclass[tikz,border=12pt]{standalone}

\tikzset{every picture/.style={line width=0.5pt}}


\begin{document}
\begin{tikzpicture}[x=0.75pt,y=0.75pt,yscale=-1,xscale=1]
   \draw  [fill={orange},fill opacity=1 ]  (220, 190) circle [x radius= 120, y radius= 70]  ;
\draw  [fill={green!50},fill opacity=1 ]  (200, 190) circle [x radius= 56, y radius= 32]  ;

\draw (120,135) node  [align=left] {$A$};
\draw (255,167) node  [align=left] {$B$};
\end{tikzpicture}
\end{document}