Code review comment for lp:~fboucault/ubuntu-ui-toolkit/ubuntu_colors

367 +void UbuntuComponentsPlugin::registerQmlSingletonType(QQmlEngine *engine, const char* uri, const char* typeName, const char* qmlFile)

Is it really a singleton? You can still use UbuntuColors { } right? The qml component doesn't keep track of its instances. Also, the function name may cause some confusion with qmlRegisterSingletonType(). What about registerQmlContextProperty() as a function name?