There are very few different poisonous snake species anywhere in the US. (You don't have to worry about the coral snake in Massachusetts.) I'd suggest learning what poisonous snakes are in your area and how to identify them. You don't have to learn how to identify all the non-poisonous ones, just the few ones that are dangerous to you.
I don't rely on colors and markings exclusively. Sometimes the patterns can be a little hard to see and the colors can vary widely. If the snake has a pencil shaped head (other than coral snakes) I know it is not poisonous. If it has an arrowhead shaped head, it is real suspicious. An arrowhead shaped head does not absolutely, without a doubt, for sure, every time guarantee that it is poisonous, but it is worthy of a lot of respect.
I don't know what your state laws are. In Arkansas, it is illegal to kill a snake. If I find a poisonous snake around my house, well, they can fine me or throw me in jail. If I find a non-poisonous snake, I appreciate the insects, amphibians, other snakes, and rodents it eats. If I find one that I am not sure of, I take a lot of effort to identify it before I act, if I can.