Not exactly true. Companies do color code but there is not an industry standard. Each company is free to use any colors, in which ever order they like. It looks like you would be better off going by the dates on the bread.
Bread is delivered to the store fresh every day - the twist tie colors tell you the day it was baked. Monday = Blue Tuesday = Green Thursday =Red Friday = White Saturday =Yellow make sure you ask the store for their color code.