Andrew, I admire the fact that you have put so much thought into your response. However, I feel that you have overlooked the social and human factors at play here. It seems that you, like me, think very much think in black and white. And like you, I intend to tread lightly.

When it comes to terminology, if it has to be addressed, I believe the focus should be on not using color-based identification terms for humans. None is of us is white or black anyhow - we are all on spectrum of skin-tones, which don’t go to the extremes of white or black.

I completely agree with this. Human skin - even on the same person - is not just one colour, and any attempt to define people in this way is, in my view, completely ridiculous. Having said that, societies all around the world have used such definitions for centuries and they are deeply ingrained into our cultures, so I'm not sure it can be ignored so easily.

As for technical terminology, it doesn’t in any way connect colours with humans, and uses them on their own merit.

Again, I agree that when the technical terms were coined they were not intended to be connected with humans, they were simply chosen because they were already commonly used figures of speech.

Pure color white is produced when all light with colours mixed is present. Pure color black is produced when there’s no light present, hence no observable color. These are fine metaphors for things like blacklists/whitelists.

I'm not a physicist, but I'm not so sure that the properties of light necessarily work as a good metaphor in this case. If you imagine that all of the users of my UNA site are photons and I choose to block only some of them, then I will surely be left with a colour along the visible spectrum. Only if I allow all will I have white light - and only if I block all will I get black.

Same with master-slave. These are terms detached from any human subset, historical narrative or social perspective. These words mean primary and subordinate in this context and that’s all there’s to it.

Again, I agree that the intention of these terms was not to invoke images of human hierarchies but it inevitably does. I don't think you can detach terms like "master" and "slave" from a human meaning. Go out on the street and ask people (at a safe social distance) what they think about when you say "master" and "slave". Depending on where you go, most people will either tell you about the forced transportation of Africans across the Atlantic, or about BDSM whips, chains and dungeons.

Should we ban black shoes and white hats? Surely it’s insensitive to have black colours under our feet and white above our heads. 

This argument is not coherent because it is not universally accepted that feet are inferior to heads (I wouldn't want to lose either), or that above is superior to below. A blacklist always blocks and a whitelist always allows.

Personally, my message to all people identifying as black or white is - please, look within, you’re not defined by the colour of your skin - you are much much more than your body and even your mind - don’t limit yourself and appreciate that we are all connected and all worthy as equal parts of one.

This is a beautiful message and one that I almost completely agree with. The difficulty is that our society often does define people by the colour of their skin, whether internationally, or more subtly. It can be hard to achieve your full potential when you live in a society that sees you first by the colour of your skin and only second by the content of your character.

It's difficult for me to comment further. I'm sure many black people don't care what terms are used and many more would rather not be patronised by the virtue signalling of (mostly) white men. There is no answer. Changing a few terms is unlikely to change anything on it's own, but at least it gets us thinking.