Spring Tool Suite: How to hide blue color bottom border of selected file

Question

How to hide blue color bottom border of selected file, as shown in the below image, I am using Spring Tool Suite 4.

Answer 1

There is no UI to change this, you will have to edit the Eclipse CSS.

The CSS is in the "plugins/org.eclipse.ui.themes_xxxx/css" folder in your Eclipse installation (xxxx varies depending on your Eclipse release).

For the dark theme I think this is probably the CTabFolder.active selector in the e4-dark_tabstyle.css file:

CTabFolder.active {
    swt-selected-tab-highlight: #316c9b;
    swt-selected-highlight-top: false;
}