It said it had “greyscaled” its website, as well as others including the Network Rail homepage, as a “mark of respect” following the Duke of Edinburgh’s death on Friday.
But the temporary design — which was reversed by 10am on Monday — left visually impaired rail users unable to read the text on the website, which is used for journey planning and booking tickets.
Keith Barrow, editor of the Today’s Railways Europe magazine, tweeted: “This is just too much @nationalrailenq. @CrossCountryUK website is the same.
“A lot of people struggle with low contrast text - it would be good if the rail industry could pay its respects without needlessly discriminating against some of its customers.”
Other Twitter users said the switch as “discriminatory against visually impaired people” and “made it virtually impossible ... to use the website”.
The Partially Sighted Society charity’s chief executive Anita Plant explained that greyscale “generally does not work for people with sight loss”.
She said: “Having looked at the site I can see how people with sight loss will find this difficult for the following reasons — there are no accessibility options to increase the text size or change the colour contrast.
“Greyscale generally does not work for people with sight loss. Text needs to be clear black on white or black on yellow and preferably a non-serif font such as Arial.
“The white text on the grey background is incredibly hard to see for someone with a visual impairment and having text on pictures is confusing and the images themselves are visually confusing.”
Meanwhile, Royal National Institute of Blind People (RNIB) innovation lead Robin Spinks said: “Good web design and adherence to inclusive design standards is a must for all digital content creators.
“Appropriate colour contrast makes sense for every person accessing a website and is especially beneficial for people with sight loss.”
National Rail said, in a tweet pinned to the top of its feed: “The National Rail website has been temporarily greyscaled as a mark of respect following the death of HRH Duke of Edinburgh.
“We are listening to feedback about how people are using the website and are making further changes today to make it more accessible to all our customers.”
However, its website — as well as that of Network Rail — has now reverted back to the original full colour design.
A Network Rail spokesperson said: “We temporarily made our website greyscale as a mark of respect following the death of HRH The Duke of Edinburgh.
“We’ve been made aware this has caused problems for people accessing the content so it’s now back to its usual look. We’re sorry it’s caused issues and we thank everyone for their feedback.”
Other organisations who have also ‘greyscaled’ their websites today include the Office of Rail and Road (ORR), the London Assembly and CrossCountry.
Meanwhile, the BBC has taken down an online form set up to process complaints about blanket coverage of Prince Philip’s death.
The broadcaster suspended its Friday schedule across both BBC One and BBC Two to run a series of mirrored special programmes about the duke, who died at Windsor Castle aged 99.
According to the Guardian, the dedicated form was taken down after the number of complaints reached a peak over the weekend.