Yellow is associated with King Bhumibol and his birthday, and is often the colour used to represent him.
Pictures showed King Bhumibol doing some of his favourite activities - as an avid musician, photographer and nature explorer.
He is also pictured in a cartoon with presumably his favourite dog, Copper, in his lap.
Copper, adopted as a stray puppy by the king, who was often pictured by his side, but died in 2015.