Withdraw in the editor of Android Studio

The yellow in question is actually a lint mark indicating a possible problem or improvement that can be applied to your code. You can read more about how lint works in documentation , as well as ways to set it up.

Warnings can usually be ignored, but it is best to read them, understand the possible implications of the problem, and apply the necessary fixes. In fact, some fixes can be applied automatically by pressing alt+enter .

In this particular case, lint is probably indicating to use string resources , which, among other advantages, makes it easy to translate your application into other languages.