Switching between 14k yellow, 18k rose, platinum or silver changes how a piece looks and what it will weigh, and the viewer shows you both. Denser metals mean a heavier ring from exactly the same design, which is worth knowing before you commission one.
What it does not change is what you pay here, because you are buying the design and not the material. Your jeweller prices the metal, and they price it on the day the work is done, from the weight the specification sheet gives them.
Every metal is rendered under the same lighting, at the same exposure, from the same measured geometry. That is deliberate. If the presentation flattered one alloy over another, comparing them here would be worse than useless: it would be misleading at exactly the moment somebody is trying to decide.