If eyes shine in the forest and no-one is there to see them, can they still break your heart?
A central character in Isabel Allende's book La casa de los espíritus has green hair. Not dyed, not moss-covered like a sloth, but naturally green. They made a film of the book, with the same bad translation of the title, in which they expected us to believe that Santiago de Chile (and its trams) looked like Lisbon, and in which Clara was played by Meryl Streep. (Of course she was: it was 1993.) So as a variation on Meryl Streep having a new accent for each new film, she had a new hair colour. It was done fairly in a fairly subtle way, but there was a recognisable green shimmer against a medium-blonde background. Not a natural colour.
But hair can be naturally green, and look perfectly normal. People don't notice. Just as they don't notice when the sky is green: it is hard to see what you do not believe in. I know this from my own experience. When I was young and unexpectedly beautiful, I had green eyes and blond hair. Not emerald green, not platinum blond, or even ash. A swampy kind of green, and a more subdued kind of blond. If you looked carefully enough, in the right light, and forgot what exactly you were looking at, you could see that they were essentially the same colour.
I had green hair and blond eyes. It's less uncommon than you might think.
I wouldn't want you to think I spent hours in front of the mirror, obsessively peering at my eyes and hair. (I'm not saying I never did, but I wouldn't want you to think it.) There was someone who spent a lot of time looking at me at close range, and she told me.
Colour vision is a fascinating subject, about which much has been written, most of which is wrong or at least oversimplified. As will be anything I say now. Our modern understanding starts with Newton's Opticks, which tells us that white light is a mixture of (literally) all the colours of the rainbow. Further investigation shows that by mixing just three pure colours of light you can create something that will look like any of those rainbow colours, and many others lighter, darker, sludgier or browner. This fact sometimes leads to claims that all colours are 'made' of three primary colours, or that the three kinds of cone cells in the retina of our eyes are sensitive to red, green and blue light. Philosophers burbling about sensory perception have been known to go on about a particular mixture of wavelengths leading to a particular colour of sense data. But all of this is, of course, bollocks. (Please pardon my use of the technical term, but I am, after all, a philosopher myself.)
Many different mixtures of wavelength of light can be perceived as being the same colour, and they need not contain any red green or blue light at all. All that is required is that they produce the same level of response in S M and L cones in the retina. And those three kinds of cell do not respond only to blue, green and red light respectively: M and L cells respond to some extent to most of the visible spectrum, and even S cells to about a third of it. But even if the response is the same at the cellular level, there is no guarantee that the colour perceived will be the same: the colour you see something as being depends on the colours of the things around it (and vice versa. Things must get pretty complicated in there). And there are all sorts of automatic compensations for the quality of the light, whether something is in the shade or not, and so on and so forth. Vision is such a wonderful complex system, it's no wonder things sometimes go horribly wrong.
All this to lend some kind of plausibility to what comes next.
I mentioned there was someone who looked rather closely at my eyes, for a while. Several times. By daylight, by candlelight, by streetlight and by twilight. Sometimes she told me the colour of my eyes as she was seeing it. When I was happy, when I was sad, when I was tense, when I was relaxed: she told me how the colour changed with my moods, as well. Normally the colours were different kinds of green and brown, with occasional excursions into the grey zone. But one day, by twilight and by love, she told me they were violet.
Maybe if my eyes had been better, I would have seen all the changes that hers went through, as well. I only saw them vary between beautiful brown and beautiful black. I'm sure there would have been a lot more to see with different eyes.
But how could you know what different eyes could see? How do you even know if other people see the same when they are looking at the same colour as you are?
These kinds of question annoy me. Not because they are stupid, as such, but because in my experience, the people who ask them are not prepared to take an answer seriously. Which to my mind suggests they are not taking the question seriously.
Looking at the first question first: we do in fact know that there are animals that see different colours to us, and we have a pretty good idea of what those colours are. Most daylight-active animals apart from mammals have four kinds of cone cells in their eyes rather than our three, with one kind sensitive into the ultraviolet. Experiments have been carried out to see what colours birds can see by first training them to peck at a lever for food if two lights are showing the same colour, then showing them one light of a single wavelength and another with a mixture of colours, and then varying the mix until they peck. Sometimes they peck when the lights look different to humans, and sometimes they don't peck when they look the same. So we know that birds don't see colours the same way that we do because they do not react in the same way to colours we perceive as the same.
Similarly, we know that colourblind people must see different colours from those with normal colour vision. And in general, we know how to tell if someone or something is not seeing the same colours as we are. So, to come back to that second question, failing to acknowledge that we are seeing the same when there is no reason to think that we are seeing anything different is just ... annoying.
There are good reasons that we use metaphors of seeing for knowledge and wisdom, however insulting to blind people it may appear to be. (Although none of the blind people I've known have complained.) Faced with the same situation, different people become aware, or fail to become aware of different things depending on what they know and what they have seen before. Some just see more. 'Wisdom' is derived from the same word as 'vision.'
When I was young, green, blonde, and careless, I thought people should decide what they wanted for themselves, even if what they wanted was me. I thought I would want the same. But I was already damaged and didn't know how many ways there are for people to break. There are things I see now that I could not see then.
So I let her follow the colours of my eyes for a while, and then left her to try somewhere else. And there, someone else saw my eyes in violet. And I stopped leaving, so I never went back.
Memories fade, but the colours do not. I know she still thinks of me sometimes, and I know some of the colours she sees. But one thing I never thought to ask: did my hair change colour to match my eyes? Does she dream of a lover with violet hair?