They're showing green numbers the system is detecting them as an upgrade it doesn't detect what you have on your generator already, the generator mods show green stats for lower mods than the crafted ones that I have.
Can confirm, if you are in your inventory all generator mods are showing as "green numbers" which will undoubtedly create confusion for new or less than experienced players.
Can confirm same thing on xbox, all the generator mods are showing up as green numbers, and im also pretty sure unbuffed with no consumables popped i am missing might from the generator mods, pretty sure normally i said at about 252k might and im only at 240k might, the math for 4 45.4 might mods would make up the difference.