I'm often surprised by the things that clients choose to base a room design around. Once I had a client who wanted to spruce up her master bedroom. The furniture and carpet were staying (and I might add, were workable). But she had just purchased a new comforter, and she insisted that the rooms's color palette be based on the comforter. Now, the comforter may have cost $200-$300. But the custom window treatments and bedding, paint job, chairs and other furnishings for the space would cost thousands. So the idea of being locked into a color palette by an item so easily replaceable and low in cost, relatively-speaking, seemed foolish. Especially because the comforter, although nice, really limited our options: it was a paisley pattern in olive (yes, olive), ivory and rust.
I have a similar situation now. I'm working with clients who recently moved into a new home. The home's former owners left custom window treatments in several rooms. These window treatments obviously had cost the former owners a decent amount which influenced my clients' decision to keep them. If you knew my clients, you'd know that these window treatments hardly suit them: they're young and hip but the window treatments are fussy and stodgy. So when my clients said they wanted to work with them, I was taken aback. We've slowly started buying furnishings for their family room keeping to the palette the window treatments inspire. Now my clients have decided, after all, that they really don't like the window treatments and want to replace them.
You may say it's the designer's job to educate his or her clients and convey the big picture (a.k.a. project scope). Maybe it's easy if you're Mary McDonald and your clients live in L.A and will do whatever you tell them to do. But in my experience, it's hard to convince clients to abandon their attachments, especially when those attachments relate to money they've spent. Perhaps this notion is specific to New Englanders -- most of my client base. You know, that Yankee mentality ("waste not, want not . . ."). All I'm saying is, if you're going to hire a designer, you should be willing to let go of attachments. It will cost you less in the end.