Configure code coverage behavior
Press Ctrl+Alt+S to open the IDE settings and select Build, Execution, Deployment | Coverage.
Define how the collected coverage data will be processed:
Show options before applying coverage to the editor: show the Code Coverage dialog every time you run a new run configuration with code coverage.
Do not apply collected coverage: discard the new code coverage results.
Replace active suites with the new one: discard the active suites and use the new one every time you launch a new run configuration with code coverage.
Add to the active suites: add new code coverage suites to the active suites every time you launch a new run configuration with code coverage.
Ignore implicitly declared default constructors: exclude the implicitly declared default constructors from coverage statistics. No-arg constructors that are declared explicitly will remain included.
Ignore empty private constructors of utility classes: exclude from coverage statistics empty private constructors in classes where all other methods are static.
Select the Activate Coverage View checkbox to open the Coverage tool window automatically.
Change colors of the coverage highlighting
Press Ctrl+Alt+S to open the IDE settings and select Editor | Color Scheme | General.
Alternatively, click in the popup that opens on clicking the coverage indication line in the gutter.
In the list of components, expand the Line Coverage node and select a type of coverage: for example, Full, Partial or Uncovered.
Click the Foreground field to open the Select Color dialog.
Select a color, apply the changes, and close the dialog.