[MFC] Thin Caption Bar on Tool Palette

I'm using this:
CWnd::Create(cls, _T("Colors"), WS_VISIBLE | WS_BORDER | WS_CAPTION, rect,
pParentWnd, 0);
to create my tool palette window.

It works well, but I'd like to have a caption bar that's about half the size
as normal.
Is this possible, and if so, how do I implement this?

Thanks!
- Pete