I am assuming that it is a Datra metel variety from your description.
By Stamen I guess you are referring to the central part of the flower? A Stamen is actually the pollen bearing or male part of the flower.
There are several Datura species that have a coloured throat to the flower. Datura discolor is a nice species that has bicoloured flowers. I think the most showy species with large flowers would be Datura metel. There are several colour forms of Datura metel, including white or cream with purple as well as a solid yellow.

Mike

Here is a link that might be useful: Stamen