The signs which are enabled at present are a repeat of last year's "gesture" to coincide with Pride Parade. Approximately 50 signals around Trafalgar Square have been temporarily changed.
Alison Camps, Director at Pride in London, said: "It's fantastic that London is a city so keen to celebrate Pride that even traffic lights can be used.
This small symbol is a big gesture from the Mayor of London and TFL (Transport For London), and we're delighted to have their support."
Martyn Loukes, chairman of OUTbound, TfL’s LGBT+ Staff Network, said at the time: “This illustrates TfL’s support for the LGBT+ community and London's diverse population. I am proud, as a gay Londoner that we are unveiling this now following the tragic events in Orlando [the bombing at queer nightclub 'Pulse' in which 50 people died] and our thoughts are with all those affected.”
The images are only seen when the pedestrian light turns green and are a temporary installation in the Trafalgar Square area.