Hi there! Thanks for your questions. The wall siding is a white oak finished with Rubio Monocoat Fumed. This is a specialty finish that reacts with the tannins in the oak to create a subtle greying affect. It was then finished with a clear sealant. Wood siding in exterior locations must be carefully considered to anticipate weathering over time. Direct exposure to sunlight (UV) and rain will cause wood siding to weather and possible deteriorate. Soffits are generally sheltered enough to not be a problem. Wood siding on walls require careful consideration of the degree of overhang, orientation and height. On this project the wood side of the wall is well sheltered by the roof and surrounding trees and opens to the North so it never sees direct sunlight. With a good coat of clear sealant and no direct sunlight the wood is holding up wonderfully and has not shown any noticeable discoloring or staining relative to the wood siding as it continues into the interior in the two years since construction.