What Your Canvas Maker Doesn't Want You to Know
The top of the bimini is painted white to make it cooler, waterproof it, and extend the life. The trim on the dodger shows the original color. This bimini is about 4 years old and had started to show signs of sun damage.
On sunny days the forest green canvas was a heat magnet. This is much better now that the top reflects much of the heat. I expect the coating to improve the life of the canvas and stitching as the coating will protect both from further sun damage.
The coating used is Siliconized Elastomeric roof coating I found at Home Depot. It took 2 coats and used about 2/3 gallon. I don't know if new canvas will reject the coating, but the coating is adhering very well to my weathered Sunbrella acrylic. The coating did not soak through, so none of it is visible from the underside.