Section 2. The seal of the commonwealth shall be circular in form, bearing upon its face a representation of the arms of the commonwealth encircled with the inscription within a beaded border, “Sigillum Reipublicae Massachusettensis”. The colors of the arms shall not be an essential part of said seal, and an impression from a seal engraved according to said design, on any commission, paper, or document shall be valid without such colors or the representation thereof by heraldic lines or marks.