While this is not 100% related to DIY, it is something that I had given quite a lot of thought to over the years.
I guess this is one of those “big” questions. How do we actually know that our internal feelings and perceptions match the feelings and perceptions of those we share ideas with. Particularly, how do we know that color is perceived similarly by different people. The short answer is that we don’t. Vsauce makes a great presentation of this idea.
If you don’t agree, just check that your monitor is calibrated.