[fhernand]

I don't pretend to be the final word on the subject but I have done so many of these signal colors to say that unless you have a white base sealer, to a great degree you will loose brightness and "pop" under sunlight. I have sample panels of different colors of base showing some variation of hue depending on color of base coat Using Glasurit will enhance greatly the color. So, yes for any signal light colors, white base sealer is the only way to go for me.