Simple Mode installs the mod in your steam folder, over top of any other mods. It doesn't really clean up after itself, since it really doesn't know what the mods are actually changing.
The Green icon just indicates that the folder is ready to have the mod installed, ie 7daystodie.exe exists. If it's red, in Advanced Mode, it means the target folder doesn't exist, and the Launcher will create a copy of the game before applying the mod.
If all mods are loading up True Survival, I'm wondering if True Survival is installed in your Steam folder. You can go to your steam folder, and just delete the 7days to die folder, then have steam re-validate and re-download everything.
If you re-validate without deleting, it will just update and reset all the files from Steam; it won't remove extra files it finds.