Left Keynesian economists believe in strong consumer demand, but even Keynesians know you can have too much of a good thing!
It's typically a better choice to paint the walls one of the accent colors from your bedding instead of the primary color to avoid too much of a good thing.
It is possible to have too much of a good thing.
Unfortunately, too much of a good thing always turn bad -- even water.
In the case of vitamin D and the other fat soluble vitamins (vitamins A, D, E and K), there is such thing as too much of a good thing.