Here's the actual meaning of the song, straight from John Penney himself.
"When I wrote it, what happened was I was starting to become aware of the environment. That was what ‘Grey Cell Green’ was about. A lot of people think it’s a love song. It isn’t a love song. I mean, people can have it as a love song. But what I was writing at the time was related to lots of people saying, “We’ve got to get in touch with Mother Earth. It’s in the trees. It’s all around us. We’re gonna get all conceptual and love the planet,” and I was saying, “Actually, it’s down to us. We’ve got to not chuck our crap on the floor, we’ve got to stop eating meat.” That was my thing. I was already starting to get worried about fisheries and overfishing and pumping chemicals into cows—and this is 1989! And then now, look where we are… It doesn’t please me to feel clever. It doesn’t, because nothing has changed, in fact it’s worse! I’m looking back thinking I could have pushed that point a bit more, possibly. But the past is what it is, isn’t it? But these days I do use it, I do you use it—if I say so myself, the concept of making your grey cells turn to green issues, I think that’s a decent hook for where we’re at right now."
Here's the actual meaning of the song, straight from John Penney himself.
"When I wrote it, what happened was I was starting to become aware of the environment. That was what ‘Grey Cell Green’ was about. A lot of people think it’s a love song. It isn’t a love song. I mean, people can have it as a love song. But what I was writing at the time was related to lots of people saying, “We’ve got to get in touch with Mother Earth. It’s in the trees. It’s all around us. We’re gonna get all conceptual and love the planet,” and I was saying, “Actually, it’s down to us. We’ve got to not chuck our crap on the floor, we’ve got to stop eating meat.” That was my thing. I was already starting to get worried about fisheries and overfishing and pumping chemicals into cows—and this is 1989! And then now, look where we are… It doesn’t please me to feel clever. It doesn’t, because nothing has changed, in fact it’s worse! I’m looking back thinking I could have pushed that point a bit more, possibly. But the past is what it is, isn’t it? But these days I do use it, I do you use it—if I say so myself, the concept of making your grey cells turn to green issues, I think that’s a decent hook for where we’re at right now."
Source: https://www.indiependent.co.uk/interview-neds-atomic-dustbin/