Dominant to Light Wash
Marshall hides Light Wash pulled here by Leonardos hidden Destiny Waters since Light Wash is recessive to Odyssey Collision (my previous post also shows Marshall hides Light Wash as it shows on her and Skippers last baby which clearly must hide the FC Dylan)
Marshall then bred to Skipper, Skipper shows FlowerChild Byrds already known to be recessive to Fancie Pink Diamond.
Since the baby shows FlowerChild Byrds and cannot hide Fancie Pink Diamond it must hide the Light Wash