If you suffer red-green colorblindness, or if you simply don't like the red symbols in the PDF Annotator toolbar, you can switch those to a blue color. Here is how:
Start PDF Annotator and select Extras, Settings.
This opens the Settings window. In the Settings window, on the left, under DISPLAY, click on Toolbars.
Check the Use alternative color option to see blue icons instead of the default red icons.
Click OK to confirm the setting.
As you will see, all red toolbar icons have now changed to blue.