Although the annual awareness day, which takes place on October 10, is supported by the World Health Organization (WHO), Young Minds decided to go one step further with the campaign.
The charity, which provides information and advice to young people, and parents and carers about mental health, requested that children and young people wear something yellow to school, college and university on Friday, October 8 to support its Hello Yellow campaign.
To show its allegiance to a fellow mental health charity, St Andrew's decided to support the campaign across the entire weekend.
In a video posted to social media, Katie Fisher who chose to wear a yellow coat, said: "There's never been a more important time to talk about mental health of young people. With all the challenges we've had to face over the last 18 months here's never been a time when mental health challenges have been more prevalent.
"So put on your yellow, be loud and proud and shout about mental health and wellbeing because for every person who is receiving care and treatment that they need for their mental health there are so many more people suffering, alone. It doesn't have to be that way. Here at St Andrew's we want to break the stigma and get everybody talking about mental health and shouting proudly about Hello Yellow, the Young Mind's campaign."