True, but a day on Mars is pretty much the same length as on Earth, which is great for the human cycle. Googling says that lux 100k on Earth would be roughly 44k on Mars, so a lot dimmer, but still better than months of darkness on end.
Now the real question is whether colonists can/will live on the surface? But then a secondary addition, due to modern technology we now have much better lighting that can approximate natural lighting, even underground.
In every book I've read on the subject they mentioned going underground to protect against radiation. The lack of a thick magnetosphere apparently means any surface equipment / personel would be subject to unacceptably high quantities of solar radiation. I guess living in a hole on another planet isn't as glorious as giant geodesic glass domes but I sure hope somebody does sign up for it.
Now the real question is whether colonists can/will live on the surface? But then a secondary addition, due to modern technology we now have much better lighting that can approximate natural lighting, even underground.