Colourful Hat

This is what you call a busker cap, basically a baseball cap which has a pillbox shaped crown rather than the normal domed crown.

This was Christmas present which I yet to wear other than in the photos here, its always a problem when you have more than a few hundred to choose from.

The lemons also came as Christmas gift the same year and seem to go with the very colourful hat, also suiting the colourful top I'm wearing.

Military Style Cap

This cap is what you get if search for military style caps, if differs from a baseball cap because the crown instead of being rounded skull cap shape, it is pill box shaped. 

Military in style, but not actual military hats.

They are normally found in kharki, browns, olive and other military colours, but you can also get them in anything from pink to leather depending on your taste. 

They don't tend to have logos prominent on them.

They also come under the titles Army Caps, Cadet Caps and Busker Caps