I sure hope this is a prank or a side effect. Like, they wanted to greyscale some part of the page to give those 0% cheapskates a sad smiley face.
Because doing it this way is not not only unprofessional, it creates support issues. In other words: it costs money because people not reading this thread will open a support ticket.
If they want to encourage more money flow by this, as a user I would like to see a tip to Itch button where payments are made. Right next to those buttons.
Support the developer by paying above the minimum price
+$1.00 +$2.00 +$5.00 +$10.00