> dark energy is only dark because it doesn't interact electromagnetically That's certainly the case for dark matter. After decades of work we still don't know

> dark energy is only dark because it doesn't interact electromagnetically That's certainly the case for dark matter. After decades of work we still don't know what it is, which has given the word "dark" the additional meaning of 'unknown'. When it comes to dark energy, I think it mostly implies this second meaning.