Karen,
I too do the same, I know alot but forget as much and learn alot from questions, that's half the reason I enjoy this site so much.
Testing my memory here: You are correct that scale has soft shells too but I believe when they are the soft shell they are greenish color (light color, blend in with the stem or leaf color) and they have some type of legs that allow them movement. Then in the adult stage they loose the ability of their legs and then turn a hard shell and no movement and then are the black and or dark color.
Thanks for the for all your input!!!!!!!
Weezie