I have found that Prismacolor has changed their formula over the years...there may also be different levels of quality pencils as well...but I still have the originals I bought many years ago....they only have numbers on them, they don`t have the scripted name of the color printed on them....I find those were much better quality than the newerones I own plus....sometimes the same color, from different boxes, are a little different. I`v bought several boxes of 60 over time and noticed that.
Recently I have found some Mitsubishi colored pencils that are outstanding, I can`t find higher end Prismacolors in this Japanese city, if they exist...but once I get back to Canada for good I`ll look around to see if I can find different models from that makers, they`ve been my go to`s for decades....but the Mitsubishis really are very good too.