Introducing my LEGO Parts Guide, which is powered by images exported from LDraw.

[tom alphin]

But those are not Q-Parts. Q-Parts are standard parts with colours only available for the Legoland model builders

In an ideal world, websites like BrickLink or Rebrickable (which show which colors a given part comes in) would have a database of known non-production q-element colors.  That said, I don't think this would be very useful, nor easy to maintain, since we would be trying to maintain a database of what basically amounts to stolen LEGO parts.

P.S. I have heard two slightly different definitions of q-parts...  anyone know which is correct?

1. Any part in a non-production color available to LEGOLAND model builders is a q-part or q-element.
   
2. Q-parts/elements are those parts which are produced in a full range of colors for LEGOLAND - so a Q-Part is a specific part shape that the company has decided is useful enough to provide to model shops in all colors.   (If this is the right definition, I would LOVE to see a list of which part shapes are defined as Q-Parts, because it is a signal that TLG sees the part as crucial to general-purpose model building.)
   

---Tom