ScrollMagic makes debugging easy.

Open your javascript console to see all the helpful information ScrollMacic logs, if told so by the loglevel option.

To help you visualize the parameters of your scene, ScrollMagic comes with a debugging plugin. It lets you add indicators to see where the scene starts, where it ends and where the trigger hook position is.
You can see them in all the examples (look to the right) and they require the inclusion of an extra JavaScript file (plugins/debug.addIndicators.js).

view source
Console Output

I'll be black!

view source