The June update recently added a rare chance for Painted items (wheels/toppers with different colours) or Certified items that track a different stat than usual to drop after matches. I wasn't able to find any information on whether or not trading in my existing toppers (e.g. 5 uncommon --> 1 rare) can result in a Painted or Certified topper. Can anyone advise as to whether they have obtained a Painted/Certified item through a trade-in as opposed to a random drop?
It is most certainly possible to get a painted and/or certified from a trade up. Below are two video examples of getting a painted, and then a painted and certified item from a trade up. These items are from the latest Turbo crate but the rules apply to any items traded up.
I've gotten a painted Drink Helmet (it was yellow but had a fancy name to it) and I ended up trading a drink helmet, and 4 dominus royalty's for a Hearts trail, so I cannot provide a screenshot. But trust me, Psyonix also said that not all toppers are painted, but you know...
Yes, it is possible. I managed to trade up some old uncommon toppers and got a painted zeta, no doubt you can get certified too.