Monika, I watched that video last week and had much the same thought as you did. Neutral colors are nice and natural and calming, but isn’t there color in nature and that makes people feel joyful.
I would never encourage fill a classroom with primary colors, but maybe a restrained use of color should be encouraged.
I’ve also been one who believes in a more stripped down environment, but in this video she talks about abundance and I know there are times when I have seen children rejoice in abundance. I think if we consider carefully what materials we can provide a sense of abundance with, we could occasionally bring this sense to the children. As you can see I haven’t altogether formed my thoughts on this one, but it is something, I’m reflecting on.