It seems like Pink would be the most altruistic but it would soon require you to spend every waking moment trying to heal everyone in the world. I'd imagine there would be people showing up wherever you went, probably at your home as well, begging for you to heal a loved one.
It might also have the unintended consequence of hindering medical advancements. For myself, the very first thing I would do is cure my son's diabetes. But if over the course of several years I'm able to also cure diabetes around the world then there would no need for researching and developing better insulin and medical devices for testing and regulating blood sugar. Fast forward several decades to once I've passed on and suddenly there is a huge uptick in active diabetes cases and there is no longer the research, development or supply chain infrastructure to handle it. Whereas had there not been a healing power there would be better treatment and maybe even a cure.
Both Blue and Orange could be both fun a useful without causing the same kind of issues or guilt. However, I think Grey would be the best choice because I could theoretically also levitate and propel myself along with other objects so that kind of simulates flight and super speed along with super strength and force fields. I never thought of telekinesis as being on the same level as lots of other superpowers until I saw the movie Chronicle, now I'm thinking it's the most versatile.