使用\renewcommand{\CancelColor}{\color{whatevercoloryoulike}}
应该有帮助!
thicklines
我建议也使用该包的选项:
\documentclass{article}
\usepackage{xcolor}
\usepackage[thicklines]{cancel}
\renewcommand{\CancelColor}{\color{lightgray}}
\begin{document}
\[a+\cancel{b}+c\]
\end{document}
![在此处输入图片描述](https://i.stack.imgur.com/jd0BC.png)