How can I configure the font size for the tree item in the package explorer in Eclipse?

Question

How can I configure the font size for the tree item in the package explorer/outline in Eclipse?

Which item in Font under Preferences I should change?

Answer 1

Eclipse v4.5 (Mars) using the built-in dark theme on Linux.

eclipse/plugins/org.eclipse.ui.themes_1.1.0.v20150511-0913/css/dark/e4-dark_globalstyle.css

Around line 204, you can add your chosen font size:

background-color: #2F2F2F;
color: #CCC;
font-size: 8;