What goes up, must come down.
These types of errors really got me interested in EFOs. I am fairly selective picking ones based on visual appeal. The other noteworthy thing, is that many EFOs can be had relatively cheaply even if they are uncommon.
Modern issues have had a lot of different errors in printing, but you will often find more extreme versions available if you hunt. The ones I have posted here (except for the normal runner in the jpeg) are some of the more extreme color shifts I have seen in this Olympic issue in the last few years.
Lastly, I am thankful to the moderators of this new forum for finally creating this and hope it will thrive!