Remove themes from Chrome

I am using Chrome web browser on MX Linux 19.2. I installed a theme from Chrome Web store. For removing an installed theme, you have to go to settings and click on appearance. There is an option to reset to default theme. But, in Linux version, this option is nowhere. It only shows a button to shift on classic or gtk+ theme. When the theme is changed to classic or gtk, the theme installed from store is simply disabled, but not removed. How can I remove it ?