Fix incorrect use of default gui context in ColourPicker.
Fix incorrect use of default gui context in ColourPicker.

--HG--
branch : multi-root-devel

cbeck88/cegui-mirror-two,cbeck88/cegui-mirror-two,cbeck88/cegui-mirror-two,cbeck88/cegui-mirror-two,cbeck88/cegui-mirror-two