i saw in the walkthrough that corruption points affect how the girls react or something like that and i want to go with romance route but like you said and like i suspected "blue" (i don't know how in the picture it turned green, my old screen mixing colors i guess) or green means the right decision but it gives corruption points alsoI agree.
The red/blue wasn't really necessary...
bombo
To answer your question.
Green = yay
Red = nay
There isn't really any corruption in the game though.
The only thing that might qualify for that would be the Bella "corruption" path. Lains/Ashram mod should give you a warning for it.
Personally a path I'd never go cause it sucks.
im frustrated