Tire covers?

Will they help my tires last longer?

My TA/KO tires are a year old. I don't put a lot of miles on them, so they will definitely die of old age before they wear out.

Should I get covers? Canvas or vinyl? Is black ok or do they need to be white to reflect light?

I mostly stay in the sunshine, and I see a review on Amazon says that vinyl is bad in the sun, canvas is better if they will not get rained on much. Is that accurate?