I'm sorry, what?
None of this makes sense
There isn't a 'target market' for white walls, the whole point is they are designed to be a blank canvas so you can imagine YOUR OWN taste. As the pp pointed out, many people struggle to do this with any form of decoration/colour so the idea is to make it as easy as possible to do so.
Why on earth would the colour of the walls make it hard for you to remember the size of a garden? And if the white walls are so overwhelmingly confusing, it's not 1984 anymore, you can look on rightmove/zoopla to remember the layout and garden size if you really are choosing between that many possibilities.
And most importantly, wtf does your 'circle' have to do with anything? Why would you know or even care about what your friends think of the decor of a house they aren't even going to live in and you might redecorate before they even see? Are you only allowed to be friends with people who like the same colours as you?
"The new woman at yoga seems nice, shall we invite her out for a coffee after?'
"Better not, I heard she has a magnolia kitchen..."
"Seriously? Wow, good thing you told me. You're right of course, clearly not Our Sort at all...."