Is it possible to create a new Game Attribute ?

There is no Colour or Control Type, for example.

http://www.stencyl.com/help/view/game-attributes/

you can create colour types with "set game attribute text   with anything"

but the problem is that is you want to save and then load the attribute, it causes problems.
That's why if you use the ave and load feature, it 's better to convert them  into a normal String/Number/Boolean/List/Map type