Green.
Normally green and white
Signs that alert you to service areas such as rest stops are normally blue or green.
Usually a noticable orange.
Road construction signs are normally orange in color with black print. They warn drivers of road closings, upcoming stops, and detours.
Signs intended to warn you of a hazard may be called "safety signs" by some, and they are red and yellow in color. Safety signs that are intended to tell you that something is "safe" are green in color.
yellow
there are mostly yellow.
white
brown
Green
All signs which actually contain the element neon are about the same color. However, some signs which contain elements other than neon are sometimes referred to as 'neon' signs. In this case, the signs with different elements are different colors than true neon signs.
red