yellow sps question

[Borderjumper]

I had a retailer add a "yellow pimple encrusting monti" to my last order.. sight unseen. It was described to me as bright yellow with white polyps. Well.... it has white polyps.
Its tan, with a hint of light greenish yellow around the edges. If anyone has something like this.. where do you keep it in your tank to get the yellow to color up? Ive tried it high.. its tan. Ive tried it low.. still tan. Any ideas?