Lemon blossoms smell like a pale yellow. Even though they're really white. Or do they smell yellow because I know they will eventually be lemons which are yellow? It's difficult to divorce preconceptions from the sensory impression. It would be easier to get a color impression with a blind sniffing.
Big fat magnolia blossoms smell pale, pale yellow (faintly lemony).
Freesia blossoms smell very yellow, too.