[rules-users] Enumeration in Guvnor

Hi All, i have a java class 'Car' with attributes ' String color' and 'int value' inside a package 'example.test'. I created a model.jar containing 'Car class',uploaded to guvnor for defining rules. For 'color' attribute, I created a enumeration like: 'Car.color' : ['red', 'blue','green'] But when i try to define a rule, this enums are not shown as drop down list. What would be the problem? Could anybody give some hints to solve this? Thanks Shekar