40 CFR § 211.106 - Graphical requirements.
(a) Color. Unless EPA requires otherwise, the product manufacturer or supplier must determine the colors used for the label background, borders, and all included letters, numerals, and figures. However, the colors on the label must contrast sufficiently with each other and with any information or material surrounding the label so that the label and the information within it are clearly visible and legible.
(b) Label Size. The prescribed label must be sized as specified in regulations published under this part.
(c) Character Style. Except when specified otherwise in this part, all letters and numerals that appear on the prescribed label must be Helvetica Medium.
(d) Character Size. All letters and numerals that appear on the prescribed label must be sized as specified in regulations published under this part.