答案1
作为起点:
\documentclass{article}
\usepackage{tikz}
\newcommand\circlednumber[3]{\tikz[baseline=(@n.base)]{
\node (@n) [minimum size=1.2em, inner sep=0pt] {#1};
\path[draw=#2,semithick] (@n.north) arc (90:270:0.6em);
\path[draw=#3,semithick, dashed] (@n.north) arc (90:-90:0.6em);
}}
\begin{document}
step \circlednumber{3}{blue}{red}: blah blah
\end{document}