Left to right we have the snowy-aqua color that is believed to be the "end of the line" color at Brookfield, circa 1919-1922 or so. In the middle is a yellow green, and on the right is an olive green. What would the dates be on these colors?

Note that the profile on these is identical to the insulators [id=374880824] which implies that this profile lasted from shortly after 1908 until the end of production.