Cynthia, I would start with species and go from there, it's a way you know exactly what's in the gene pool. Hippeastrum parodii, Hippeastrum evansiae both have yellow tones. H. viridiflorum is quite yellow but sadly it isn't available, it's probably the most truly yellow species I've seen being similar to a lemon. My guess is if this plant every becomes more available than we will have those truly yellow hybrids we're looking for! Josh -- http://www.fortheloveofbulbs.blogspot.com/