When and where did this green utility van appear in the series?

So Bachmann made what they called a “Green Mail Car” that’s a green version of the regular red mail cars with envelopes on the side, which still looks good, no doubt. Kinda wish it was brown like in the early seasons. I got two of these on the way and thought about recording them to look like that.

Even though this is the decision that Bachmann made, I can’t for the LIFE OF ME, find where a green utility van is. I’ve seen the brown one, the cream colored with red lines one, and a red and blue one in the CGI series. But no green.

Does anybody know where and when in the series do we see a green utility van, despite it being called a “mail car”?