The NHS has asked people to stop posting rainbow pictures to the new Nightingale hospital in London after a social media request went viral.
The nurse who started the campaign said she wanted to create "a sign of hope" for patients and staff.
The rainbow logo has become a symbol of support for people wanting to show solidarity with NHS workers.
NHS Nightingale is a field hospital that has been set up at breakneck speed and will have 4,000 beds.
It is now asking people to share their rainbow pictures digitally only.
In an email to the BBC, the staff nurse, who said she was based in Birmingham, wrote that she had "organised a small team" to help her coordinate the artwork and hoped to get enough to share with other temporary hospitals as well, once they are set up.
She asked for pictures to be laminated before they were sent in the post.
Hundreds of parents took part, asking their children to draw rainbow-themed pictures, laminating them and sending them in.
However the NHS has asked people to share them online instead, using #RainbowsForNightingale.
On its social media channels it referenced a"fake" Facebook account but has since told the BBC that this was not the nurse's rainbow appeal, and added that the false account has now been removed.
Unfortunately, a fake Facebook account has been set up for the Nightingale Hospital London asking people to share rainbow pictures. Please be aware of misinformation and only get your information from trusted sources, like https://t.co/R3azksNgt9— NHS Nightingale London (@NightingaleLDN) April 1, 2020