Why countries don't have purple in their flags

Why Countries don't have purple on their flags

Purple is a great colour so why is it not on any of the country flags?

It was just way to expensive! 

up until the 1800's purple was worth more than gold!, even Queen Elizabeth The l forbid anyone to wear purple except close members of the royal family. Purple= Royalty and wealth, fabric traitors would obtain a small sea snail it was a lot of work to make the dye you would've needed 10,000 snails to create a 1 gram of the dye.

Purple also represented spirits and holiness from Ancient emperors and kings and queens who wore the colour, But the dye was to expensive and even royalty! a pound of the dye would cost three pounds of gold 92,181.10 NZD  (now)

In 1856 an eighteen year old chemist William Henry Perkin accidentally made a purple dye when he was trying to make an anti malreyin drug

Thank you for reading this hope you learned a lot have a great day Bye!!