The National Rail website and app both had all colour removed as a mark of respect after the Duke of Edinburgh passed away on Friday. Both have now been returned to their normal colour schemes.

But the move to temporarily abandon the usual easy-to-read screen with white-on-blue as well as black type was met with anger and confusion by rail users.

Many complained the website was difficult to read, with many visually impaired users unable to use the site or app at all. Numerous train customers took to Twitter to complain.

One Twitter user said: “National rail have coloured their entire website grey to ‘mourn Prince Phillip’, rendering the whole website completely useless to people with visual impairments. The UK has completely lost the plot.”

Another Tweeted: “The issues with National Rail’s website today being changed to grey really bring home how much we need to raise awareness of digital accessibility.”

Another Twitter user pointed out: “Pretty sure Philip’s dying wish will not have been ‘make it hard for people to book a train ticket’”.

Other train operators, including CrossCountry and Northern Rail, also temporarily removed colour from their websites.

The official National Rail Twitter account Tweeted on Monday: “The National Rail website was temporarily greyscaled as a mark of respect following the death of HRH Duke of Edinburgh on Friday. We’ve listened to feedback about how people are using the website and have made further changes today to make it more accessible to all our customers.”