These have been discontinued in the US, but they are still available in other parts of the world. They are sold as “Crazy Sours Skittles”. I have seen them in both Ireland and Spain so I would think they would be available in other European Countries and somewhere online.
http://www.thesweetshoponthecorner.co.uk/ViewItem.php?ItemID=479
Just thought I would pass this along in case anybody remembered these from when they were available here and missed them. I know I did until I found them.

I’m pretty sure the grocery store I work at still sells Sour Skittles, are they different than Tart and Tangy ones?

Sour Skittles are still listed on the Skittles website

Yup they’re different. The Sour Skittles sold here and shown on the website are different than the Crazy Sours. The Sour Skittles here, and for that matter I also saw those while in Europe, have a sugar coating like Sour Patch Kids and are more of a mouth-puckering sour. The Crazy Sours appear just as regular skittles, just as they were previously known are more tart and tangy than sour.