=choose(Fields!Organisationlevel.Value, "Red", "Green", "Orange", "Blue")
if it is 1 then is red, if it is two then is green, if it is 3 is "orange", otherwise is blue
Video: Section 7, 56. Program Flow Functins
it can also be combined with iif
=iif(Fields!Organisationlevel.Value>3,"Blue",
choose(Fields!Organisationlevel.Value, "Red", "Green", "Orange"))