A long time a go I set my astroligist to look for Vermillion. Ever since then I haven't been able to reset him to look for anything else. I've tried deleting the word Vermillion out, typing something in it's place and hitting search, but nothing sticks. 

I don't know if it's a quirk due to the only way I have to visit the site is a browser  (chrome) on my phone (Samsung Galaxy S5), but I would like to change it again.

Please try a different browser or / and device and make sure that no software or browser plugins block or modify the behavior of client side browser scripts. The field utilizes javascript to find the object in the list, so if anything is blocking it, it will fail to verify and submit the form.

Javascript wasn't blocked in Chrome and there were no plugins. I was able to try Firefox and get it to change though. I currently have no other way to get on the site than my phone so trying another device wouldn't have worked. It's just weird that it was staying locked in Chrome.

One more thing that I forgot to mention, though it's an obvious one. You may also try to clear you Chrome cache just in case if a corrupted javascript file was stored.  

Apps can become buggy due to the big variety of touch devices and modifications of their OSes. If it's not a cache issue, let's hope that it gets fixed with the next app or OS update.