Translations:Theme editor/15/en
From LimeSurvey Manual
The preferred way to create a new theme is through the Theme Editor (see below), which is located under Configuration on the top toolbar. Some users prefer to work directly with theme files so that they can use their favorite text editor instead of the web interface. In this case, still use the Theme Editor to first create your new theme. This will create a new base theme with all the files you need in the LimeSurvey_web_root/upload/themes/survey/your_new_template directory. From there you can use your text editor to manually adjust the template files.