A grayed out target means that:

• a target has no children or all children are messages (no other targets or tasks)
• a condition on the target evaluated to false, so the target didn't execute
• a target execution was skipped because all the inputs were up-to-date
• all children elements (such as other targets and tasks) are grayed out

If a target is skipped there will usually be a grayed out message underneath:

Right-click a project or project evaluation and choose Preprocess to view the flat preprocessed view with all imported projects inlined. When in that view, the bottom yellow breadcrumb bar will show the chain of all imports from the root to the current file:

Clicking on any import will select it in the main tree. Pressing SPACE on any import in the tree will scroll to it in the text editor if the preprocessed view is currently being shown.