And the winner is...BLUE

 THANK YOU VERY MUCH TO ALL THE STUDENTS WHO VOTED. 

A blue heart

A blue bull

A blue sleeping bag

A blue balloon

A blue bag

A blue glass

A blue computer

A blue jumper

A pair of blue boots

A pair of blue shorts

A blue T-shirt

A blue notebook

A blue hat

A blue plate

A blue umbrella

A blue flower

A blue raincoat

A blue cushion

A blue motorbike

A pair of blue jeans