The red tinted glasses are a metaphor to explain to Sophie how people view the world and how it might be limited by something simple like the pair of glasses. It is also another way to show how Kant does not agree with the empiricists or the rationalists.

Alberto Knox experiments with Sophie in chapter 25 to show her that when she puts the glasses on, she will only see everything in the shade of red. This prevents her from seeing everything in their real colour and limits the way she perceives everything. I believe that from the very beginning, everyone saw everything in the same way but as we matured, the colours of the world we see also matured. This is mainly due to the fact that most of us are brought up in different environments with different experiences and social norms.

Empiricsim and rationalism also have a big influence as both empiricists and rationalists believe different things, one believing that knowledge comes from our mind as the other believes that it is from our senses.

Even though some people may see the world in the same colour, it is difficult to say that they see everything as the exact same as they never experience or were brought up in exactly the same way. This could also happen vice versa when people do not get along as they might have different colour lenses.

It is always a wonder to see what the real world is. Is there a right way to view it despite the fact that we have different colour lenses? Or is the way we percieve it now the way we learn to believe is the right way?