It has nothing to do with the light. It's a different seed with different genetics.
Every run i've done for the last several years is half 2900K and half 3400K. The difference caused by this are so small you need a large sample to discern it. You cannot see a difference, even if one exists in a statistically significant way.
also, if 'genotype' was the same you'd either be talking about identical twins, clones or a limited set of alleles that control a particular trait are the same and it would absolutely cause the exact same phenotype or trait to be displayed, all other factors remaining the same. That's kinda how it works - cause and effect.