The Mosquito is an extremely compact scout. Its armament consists of two heavy ion cannons that can put up a good fight against other small fighters but are not effective on bigger craft. The Mosquito relies on its fast engine to speedily fly away from unwanted confrontations. Its cockpit can hold one pilot with little room to spare.
The reason they are all grey is because they are built by the government, and the government is not very creative in the color department. (Also, I don't have many spaceship building material that isn't grey)