They're pretty much the same color.
Unfortunately I didn't know that until after I bought Yasmeen. Oh well. It was wasted money, but on the other hand I like to have polishes in groups, and so it would have been hard to decide which one to get when I have multiple ChGs and will eventually have multiple Zoyas. Anyway, pics.
Ok so let me describe what's going on here. Index-ring is Yasmeen, pinky is Let's Groove. They are the same color with the same flash BUT Let's Groove looks a bit cooler because the pinkish pigment flash particles are less diffuse when compared to Yasmeen. It gives it more of an electric look, which is pretty apparent in the bottom pic. In the top, you can see that while the same amount of light reflection is there, Yasmeen is glowing more all over. Yasmeen's bottle also has a tiny amount of gold duochrome, but don't get excited- you never see that on the nail. For what it's worth there's a Zoya that also looks just like Stella (a polish I love). For some of you out there, these differences may justify buying both. Don't. No one can tell the difference but you. Spend your few dollars on something else :p
Now for the HEALTH TIP: Splenda
Splenda is made from Sucralose, a derivative of Sucrose, so it is 'made from sugar' just like they say it is. They use a whole lot of chlorine to give it that texture and amp up the sweetness. It is marketed as a low calorie alternative to sugar and therefore great for dieters and diabetics. Here's the skinny: Sucralose is something like 600 times (no lie) sweeter than sugar. The problem is that while Splenda doesn't need to be used in as large amounts as sugar, people tend to like it so much that they use the same amount anyway. Even if you don't, it doesn't matter. Due to it's sweetness, your body assumes you've just had 600 times as much sugar, and prepares and releases Insulin enough to deal with that sugar.... but that sugar isn't there. So now there's all this excess insulin in your system. This exacerbates diabetic conditions and triggers weight retention. How cute is that, eh? A diet friendly sugar alternative that ultimately makes you fatter? A tsp of sugar is 11 calories. 11 calories. 11 calories won't harm you. It's almost always better (diet-wise) to just have the sugar instead..