Yes, you can do this with a calculated field on the Color shelf, as in the attached. I created a parameter, then a calculated field using the LAST() function to test for the last row:
IF LAST()=0 AND [T/F Parameter] = 1 THEN "Orange" ELSE "Blue" END.
One note - In Tableau 6.1, I got an "Internal Expression Error: Function '==' is not defined in the current context." error when I defined the paramter as a boolean, so make sure to define it as an integer.
That worked perfectly! Thank you :)