To most non-Scots this might very well be THE kilt, the Stewart Royal or Royal Stewart being without doubt the best known of all tartans. It is a universal tartan, i.e. without clan affiliations. Besides kilts it is very often used for skirts, decoration etc.
The Royal Stewart tartan was worn by King George V during his state visit to Edinburgh in 1822 and he later adopted it for the House of Windsor to mark the ancient link to the Royal House of Stewart. George V is reputed to have said that his adopted tartan could be worn by all members of his family, which was taken to mean all the people of the British Empire.
Due to its bright red colour you don't just blend in. You are standing out from the crowd. But, after all, why should you try to conceal that you are wearing a kilt?
A 5 yard 16 oz. "James Morrison" wool kilt by Heritage of Scotland.com