Add an expression to the colour on the text box which returns the colour. To start you off:
=iif((Fields!YourField.Value = "TOP RAIL") Or (Fields!YourField.Value = "BOTTOM RAIL"), "Red", iif((Fields!YourField.Value = "LEFT STILE") Or (Fields!YourField.Value = "RIGHT STILE"), "Blue" "Black"))
Alternatively, if you have very complex logic, you could use your query to do the work (as you have access to IN and proper CASE expressions), and return the colour you want as a value in a column. Then set the colour of the text box text to the value of that column (again using an expression).