So you're in love with Blake Lively's ring, so you too can be pretty in pink. She has a stunning pink oval diamond set in rose gold with povea diamonds down the shank. If you wanna achieve this look, look for something like a Morganite, or a Kunzite, or a light colored Topaz to get the same effect.
Here is a Kunzite. It's set in yellow gold with diamonds around it. But, to get the tone on tone effect, buy a light pink colored stone, set it in rose gold with little diamonds. Maybe even pink diamonds. And, then you can have a ring just like Blake Lively.