I know, they're amazing! I've had to order online to get the blue and green colors in addition to the pink, orange, and yellow - stores usually only have the pink, orange, and yellow. Same thing for pen colors that aren't black, blue, or red. Depending on what you are highlighting (printed inkjet material vs textbooks) the highlighters do sometimes leave a teeny bit of a smear from the printer ink, but they work amazingly well for the most part. The Frixion pens/highlighters also seem to run out much more quickly than other pens/highlighters, but I think it's totally worth it being able to erase any mistakes. Perfect for a perfectionist ;) Also, here are 2 desk pen organizers I love that you might like:
Enjoy!