I own both the 120 set of Faber Castell Polychromos and the 150 set of Prismacolor Premier, and I've often wondered what a colour comparison chart would look like across both sets of pencils- so I decided to make my own! Obviously as there are 30 more Prismas than Polys there are some colours which cannot be matched between sets, but I have done my very best to match up as many as possible, as closely as I can. I thought I would make this available to you all so that you can see at a glance which colours are similar and there's no more hunting around online for a comparison chart! This will be especially handy when you're following colour-alongs or tutorials which use one brand eg. Prismacolor and you only have Polychromos. Now you can find a similar shade!
I have scanned the page into my computer so some colours may vary from how they actually look to the eye. Some colours are not perfect matches, but they're as close as I could find. Prismacolor is in red, Polychromos in blue.
Click the image below to access the PDF file. I hope you find this helpful!