Is there any way to make these similar diagrams look more beautiful, by adding special designs, colours, etc.? I'll really appreciate if I can be helped out.
\documentclass[a4paper, 12pt, openany]{book}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\draw (0,0) circle (4cm);
\draw (0,0) circle (3cm);
\draw (0,0) circle (2cm);
\node (a) at (0, 0) {GROUPS};
\node (b) at (0, 2.4) {RINGS};
\node (c) at (0, 3.5) {FIELDS};
\end{tikzpicture}
\begin{tikzpicture}
\draw (0,0) circle (5cm);
\draw (0,0) circle (4cm);
\draw (0,0) circle (3cm);
\draw (0,0) circle (2cm);
\node (a) at (0, 0) {GROUPOIDS};
\node (b) at (0, 2.3) {SEMI-GROUPS};
\node (c) at (0, 3.5) {MONOIDS};
\node (c) at (0, 4.5) {GROUPS};
\end{tikzpicture}
\end{document}
\draw[fill=cyan]...