More text colours within a note?

I need to differentiate text within a note

I’d like to make the good text green and the bad text red within one note. Can I do this?

is there a way to put notes within notes?

Only basic formatting is provided for at the text level. So if you wish to differentiate text, use something like italics or underscores instead.

Not really, there isn’t really a concept of “within” in Scapple. You can draw boxes around notes though, with the Background Shape tool, in the Notes menu.