I was in a deli near work yesterday, and used my debit card to make the purchase. So far, so ordinary. But then something caught my eye. The payment machine was new, shiny, and had a colour screen.

Now that may not seem like a big deal, but what is the demand for colour screens in a device like this? Let’s think about a card payment machine.

– It doesn’t belong to anyone (unless the business owner also runs the till)
– There is no experiential upside – you don’t stop using it because of the interface
– It’s not a “loved” device, like a phone, mp3 player or tablet
– You enter a price (till operator) or a Pin (customer) – that’s it

So why the hell does that need a colour screen?

Is this the end of the monochrome world? Happily not. There are still a lot of basic screens around, in stereos, on the phone in front of me (a Cisco IP phone), on bus stops. There’s a lot of virtue in keeping things this way – these devices convey simple information and have no need of the advantages that colour screens can bring. But I wouldn’t be surprised if they start to change in the next round of upgrades – the march to colour screens feels inevitable.

However, there is one device that seems to be resolutely black and white: the Kindle (and obviously, it’s imitators). I don’t have one, but I like the fact that it started in black and white, and is staying that way. It has a certain old-school charm to it. Plus of course it helps hugely with battery life, which isn’t a concern for the things I mentioned earlier (desk phones, stereos etc).

Amazon don’t release Kindle sales figures, but they are clearly in the millions. This seems to me to be the last non-colour big product release.

And although reading text has a certain logic of staying black and white, television, you would think, has left that all far far behind.

Except according to BBC figures (p22) there are 24,000 black and white TV licences registered in 2009 – from over 200,000 only 10 years ago. It’s an astonishing decline, although I suspect it will be a long tail that could drift for years.

So who are the B&W TV holdouts? I can only think of one group of people for whom it makes sense: the blind. You can get 50 per cent off the licence anyway if you are blind, but half of the full price – £72 or so – is a lot more that £24, which is the half price for the B&W licence.

Except… try buying a black and white TV. I’m sure it’s do-able, but it’s not easy. Currys don’t sell them. Nor do Argos.