I'm writing unmanaged C++ for a VS2003 plugin.

There's a node in my project heirarchy which has a color property, and I'm
trying to use MapPropertyToBuilder so that I can use
CTLBLDTYPE_STDPROPBUILDER in conjunction with CATID_ColorBuilder.  I don't
want to write my own color-picker, I want to use the built-in colorpicker.  
My code in MapPropertyToBuilder looks sorta like this:

   switch (dispid)
   {
       case DISPID_MyGoofyColorProperty:
           *pdwCtlBldType = CTLBLDTYPE_FSTDPROPBUILDER;
           StringFromCLSID(CATID_ColorBuilder, pbstrGuidBldr);
           *pfRetVal = VARIANT_TRUE;
           break;

This causes a crash.  Advice?  The standard property builders (htmlbuilder,
scriptbuilder, fontbuilder, etc) are listed in ocdesign.idl but the VSIP
documentation doesn't tell me how to use them.  Also, if I want to use the
standard builder, then what type should my color property be?  A string?  A
ULONG?  A Variant?