It is a "Jacksonian" 2-piece button, showing various agricultural implements. You can view a non-excavated example of your button by going to the following webpage of Jacksonian buttons, where its emblem is listed as Agricultural. In the first "group photo" at that webpage, your button is the first button on the left in the sixth row. You must click on the photo two times, to double-enlarge it.
http://www.bysonbuttons.com/forsalepics/jacks/jacks1.jpg
"Jacksonian" buttons are an early form of 2-piece button, consisting of an applied brass rim around a brass 1-piece flatbutton. They get their name from becoming widely popular during the first term of US President Andrew Jackson (1829-37). All Jacksonian buttons are civilian-usage, not military, although a few have a "patriotic" emblem. As you'll see at the Jacksonian buttons webpage, most have a civilian emblem, such as a plant or animal.
Your button's backmark has the British spelling of the word color as colour, so it is a British-made button.