There is one called Old Yella, it is more white than yellow. Mine bloom like crazy, they have just finished here in Canada.

there is also a yellow hibiscus called lemon slice ,im not sure if it hardy or tropical but it seems I recall that is planted as an anual (not that this is true I have a bad memeory lol).
Kelley

thanks for your info.molly

Old Yella, is hardy zones 4-8, but info here on the www says lemon slice is Manihot which is planted as an annual.

Sue

I think I ordered Lemon Slice years ago and started seed and put out the flower turned out to be no bigger than daisies and looked nothing like a hibiscus as you know it.