Where’d the yarn go?

I decided to revamp a few of my older items with better accessories but I’m having a real problem finding certain yarns. Caron Simply Soft for example, at Walmart, Joann’s, Michaels.. there just aren’t any colors! Maybe 7, or 2! It’s the weirdest.  I wanted to make my big winged pony have rainbow hair but any store around here has no colors.  So bizzare.