Where did the colour come from? Over several decades, the color was changing all the time. Then in November of 1954, 47 states adopted the colour, white, as for regular colour for the centre line on the highway. Four years later, the U.S Bureau of Public Roads adopted, white as the regular colour for any new interstate highway system.
Then Manual on Uniform Traffic Control Devises in 1971, they made yellow as the regular color for the centerline nationwide. It took from 1971 to 1975 for everything to fully change over.
What is the down side of the colour change?
With yellow being the new color, it does not have as much contrast as white. This is troublesome at night time. When it was noticed that it did not have a lot of contrast that is when the shade of white was changed. To maximize the contrast the paint has gotten brighter and is highly toxic with lead chromate. That was used through the 20th Century.
Due to the toxic paint, any workers through the U.S Transportation, has to take extra precaution when they are doing any type of work that might or will disturbed the paint. There have been many changes over the the Melbourne line marking methods however this is likely to stay consistent for many more years to come.