How do you handle legends?

After over a decade using ER Studio I still wonder how people do some of the basic stuff I used to do in ERWin.  Most difficult for me is including documentation in the model that explains the model.  I frequently use the background color of a table to indicate meaning.  For instance, in a star schema I often use green for dimensions, blue for facts and yellow for lookups.  Whereas in OLTP models I often use color to group related pieces of data.  Either example means a graphical representation showing the colors and their meanings is valuable.  While I can create a series of shapes with colors and text, you cannot lock them or group them together so the all stay together.  The best you can do is use a boundary box and turn containment on. 

Why in a highly graphical interface is there no facility for dropping a JPG or GIF on the page?  To be honest, I really would like my corporate logo to be on the models.  

Hopefully, the new Idera team will find time to enhance the product they purchased. If so, perhaps they could grab so easy low hanging fruit by adding this feature.