[ExI] Red

[Ben Zaiboc]

On 26/06/2026 15:46, Brent Allsop wrote:
> > Whatever has a red (or redness) quality is just a brute physical fact 


I'm curious about this idea that molecule X (or some other physical object) has a 'quality' that results in our seeing colour Y.

We keep seeing the word 'red' being used. But that's not really a colour, it's a colour category. We can see hundreds of different reds, taking into account the various combinations of hue, intensity and brightness. 'Red' refers to anything from a very pale pink, only just distinguishable from white, to a deep dark reddish-black, and even these aren't just two colours, the barest glimmer of red could be an almost-orange scarlet or an almost-purple crimson, or any hue in between.

So if one object like a molecule has the 'red quality', does this include all the possible reds we can see, or just a specific one? Or is it a more abstract thing, like 'the essence of red' (in which case, how do we actually perceive hundreds of different reds? What extra factor differentiates them?) And is this quality restricted to what we can perceive directly, or does it include, for example, infrared?

It would be strange if these physical qualities were restricted to only what humans happen to be able to perceive, don't you think?

Orange is also a bit of a puzzle. Is that a colour in itself, a variety of red, or a variety of yellow?

Thinking about it, we can distinguish about 6 million colours. So are there 6 million colour qualities, possessed by 6 million different types of physical things?


> ... the strawbery still has the red quality, which is different from the different type of light that is reflected.  i.e. the light isn't what has the red quality, it is the strawberry.


I don't understand this at all. You seem to be saying that strawberries are red regardless of what they look like? If they reflected yellow light they'd still really be red? (I think that if you put a strawberry under a yellow lamp, without any red light shining on it, it would look yellow, but I haven't done this experiment).

I think it makes sense to say that, in the dark, strawberries are not red. Am I wrong?
What I'm saying here is that nothing has a fixed innate colour, that it changes depending on (among other things), the light falling upon it. A sheet that is white under white light, for example, will be green under green light, and blue under blue light, etc. You seem to be disagreeing.

Another puzzle is, if the 'redness' of strawberries is independent of the reflected light from them, how can we ever perceive this redness? We see the light they reflect. If there's something else that's independent of this, we can't sense it. Otherwise, we'd always see the white sheet as white, even in the dark.

-- 
Ben