What is the difference between yellow and white Xanax bars ?

The white bars are extended release and the yellows are not that's the difference however greenstone is the company or the manufacturer that makes both but my question is why would they give you the extended-release one time and then they playing yellow ones the next if they are the exact same medication? And if they do do it I'm talkin about the pharmacies I think they need to inform us patients before we take the prescription out of the pharmacy because some prefer the yellow effects and some prefer the extended release!

Both tablets are 2 mg, they are just from different manufacturers. There is no actual information with the difference between the white & yellow bars, however, I have heard some people say they rather have the white ones, or vice versa. There are many different types (colors, shape), but as far as trying to find out if the yellow ones are any different from the white ones, I haven't found anything that's different between the two: for example I thought the yellow ones were either time or extended release when I first took them, but all the research I've done through websites, and asking friends I haven't found any differences, just different colors & different companies