What is the right preposition in the phrase:
She has a detached house in a yellow colour.
She has a detached house of a yellow colour?
Color names typically use in. E.g.:
Do you have this shirt in blue?
The sky was red in color.
In is definitely the better choice. However, to my ear this particular construction is also okay (if a little unusual sounding) with of. It follows the pattern of describing something using of [adjective] [noun]. E.g.:
He is a man of mental clarity.
This is a sword of impeccable craftsmanship.
This is not usually used with the noun color, with the exception of the phrase person of color (or people of color). This is never used with a color name, i.e. you would never say "A person of brown color" (that would probably offend people, as well as sounding strange). It's also not common to include an article in this construction. We do however have the well known phrase from The Wizard of Oz, a horse of a different color.
In short, in is acceptable and of is questionable.