Following the yellow thread, I want to mention that I’ve not had any luck at all germinating Capt T by vernalization in moist peat despite a number of attempts on OP hips harvested at different stages of maturity including falling to the ground (from spring greenhouse blooms that ripened out of doors). I have kept it for months, and also tried planting anyway to see if a warm spell would help. As a pollen parent it gives lots of offspring, some of which made it into commerce despite poor hardiness (Golden Shower, Sunny June, High Noon I think). But I’ve not seen one good yellow with many petals in any crosses I’ve done. CaptT has fine-looking glossy, disease prone foliage, fading single one day blooms.
Recall that there are probably not many yellow genes out there, just some different linkage patterns and dosage effects. I’d say go for good plant traits and wide crosses.