Does the color that is most strongly reflected from a platelet depends on the angle at which it is viewed?

Yes, like in reflection on a single interface different colors are reflected in different directions.No$,$ the reflected light is refracted on multiple interfaces to an extent that there is no distinctive direction with the constructive interference of a particular color.No$,$ thicknesses of the layers are the same regardless of the angle so the constructive interference occurs in all directions.Yes, the path length of the light in layers changes with the angle and so does the constructively interfered wavelength.