When it comes to Trillion cut diamonds and the 4Cs, prioritize cut and clarity. This shape features 37 brilliant facets and a large table, so choose excellent cut and clarity for maximal shine.
Color depends on the metal setting you choose; yellow gold engagement rings work well with near-colorless Trillion cut diamonds, while platinum and white gold pair best with colorless stones.
Trillion cut diamonds appear larger than other diamond shapes of the same carat weight, so carat should be based entirely on personal preference and the engagement ring budget you have set.