English Translation
The house is painted white.
Which is a more typical reading, しろいろ or はくしょく?
しろいろ is the only correct pronunciation in this sentence structure though I find the entire sentence sounds unnatural a little.
その家は白く塗られている。
sounds more natural to my native ears.
はくしょく should be followed by a noun or in a form of compound word. For example, 白色塗料 (はくしょく とりょう) is a typical description on a DIY product package.