Color data type

Hello,

 

So it seems that the Color data type is a value type (which surprises
me).  

 

I would like to be able to set a Color variable to null (essentially,
the variable would indicate that no color has been assigned).  Is there
a way to do this?  I can't set the color to 0 (= Black).  I guess I
could choose '-1' - I don't think that represents a system color.
However, perhaps there is a better way?

 

Peter