roCodeRegistrationScreen Title Colour

I'm trying to change the colour of the title text on the roCodeRegistrationScreen but can't get rid of the grey.

registrationScreen = CreateObject("roCodeRegistrationScreen")
registrationScreen.SetTitle("Change My Colour")

I couldn't see anything in the SDK Docs: http://sdkdocs.roku.com/display/sdkdoc/roAppManager. I can use 'SetBreadcrumbText' instead of 'SetTitle' but would like to know if the above is possible?

Thanks