The photograph mixes yellow and white gold bands with different diamond layouts: full eternity, half-set, and plain metal spacers. The trick to a harmonious stack is alternating widths — pair a slim 2 mm band with a bolder 3–4 mm ring so the stack breathes instead of feeling like a single block.
Colour temperature matters. Warm yellow gold makes diamonds look slightly softer and creamier; white gold or platinum pushes a cooler, “icier” read. There is no rule against mixing metals, but limit yourself to two families (for example yellow + white) so the story stays coherent.
For daily wear, check that stones are set low enough not to catch on knitwear, and that the inner edges are slightly rounded (“comfort fit”) if you plan to wear three or more rings at once.