Looking up...
我住在一栋白色的房子里。
I live in a white house.
A house that is white in color.
她喜欢白色的房子,因为觉得干净明亮。
She likes white houses because she thinks they are clean and bright.
This is a literal description of a house's color.
In Chinese, colors are often used descriptively before nouns, similar to English.
Combination of 白色 (white) + 的 (possessive marker) + 房子 (house).
This is a straightforward descriptive phrase with no idiomatic meaning.