Vermilion vs. natural wood finish

Why are some shrines/temples painted vermilion (red orange) and others not? I researched the significance of color vermilion (it is believed to ward off evil etc.), and some site noted that elements in the dye protects the structure also.

If so, why are not all shrines/temples painted vermilion?

If I had to guess, one reason was probably simple fundraising. Vermillion paint would have been rare and expensive.

I have seen white, silver, and other colors! Just took it as variation.
No idea either.

It is made of cinnabar.

https://en.wikipedia.org/wiki/Cinnabar

It is used for many years as the color is maintained long and antibacterial.
It is very big problem to repair the color of shrine, as it is difficult to keep the safety of workers and to dispose the exfoliated ink.