CAVEAT: I have not seen the pink in person.
I was much more tempted by the pink than the green. Pink obviously goes with the playfield colors. Hell, I have metallic pink flippers on my game, so I get it. But something about the contrast of the green, and the fact that it's a nuclear reactor, made me go green.
SUPER glad I did. The green edges during the blue GI looks amazing, and unlike the pink, doesn't blend in with the rest of the playfield. The glowing green is a cool contrast to all the pink artwork.
A side consideration is they take different color GIs to activate. Green requires the blue, while I guess pink requires the teal. I think the blue GI looks cooler than the teal, so that's an added benefit. All personal preference, obviously. Someone talked about mixing the green with the pink to get the best of both, but the fact that they take different GI really nullifies this for me.