Very big problems start to arise when you want to name the color of the sphere in one word shared by all.
If at some point in time someone says "the sphere is Blue" to someone standing where it is Pink then the local perspective of the second person is erased for the supremacy of the perspective of the previous one. The second person has to understand his reality through a mediatic term that betrays his local experience of it.
There is no universal agreement possible just the extension of oneself over other selves.
Also if we find a way for the mediatic term to fit very well with our experience of the mediated object then we fall back into place. (alignement reality-mediaspace-human)