Oval Lab Created White Opal & Round Cubic Zirconia .925 Sterling Silver Ring Sizes 4-11

Does this run true to size? i measured myself to be a 7.5 using the jwlzz.com sizing chart (i hope it's accurate). should i get the 7 or 8?

How do I measure my ring size

Does thing pair well with other rings? I want to wear a band with it but I'm afraid it won't sit right since the stone is in the middle of the band.

Does the ring turn your finger green?