A push pull clasp does not make you solve a puzzle. One straight motion along the clasp opens or closes it, which is why it works so well for jewelry that comes off often.
Visually Speaking
The neutral, highly reflective surface of rhodium-plated white gold does not cast a warm color tint into a diamond's facets, allowing the stone's own brilliance to appear maximally white and intense.
Industry Insight
Brilliance and fire are distinct optical phenomena. Brilliance is the total white light returned through the crown, and fire is the dispersion of that light into spectral colors. Both are determined by cut geometry, which is why cut is the 4C with the most direct influence on how a diamond looks face-up, and why a poorly cut stone with excellent color and clarity will underperform one with average grades but an ideal cut.