Indents vs Evaps vs Faint positive. PLEASE HELP 😁

When tweaking a test, will all of these show color or only a positive? Of all the tweaked photos I've seen people put up it seems only the positives show the faint line whereas indents or evaps show a black line. Is this correct? On all 4 of my tests I have a faint 2nd line but don't know what I'm looking at! 😏😏