Can you help this man?

Greg has a long history of wearing clothes that do not match. Generally, I find this trait endearing, but sometimes I feel embarassed for him and try to help. We were getting ready to go to a local park yesterday and play with Abe. Greg was wearing khakis and a ketchup-red T-shirt. He pulled on a maroon zippy sweatshirt over the ketchup shirt. I gave him my standard “You have got to be kidding me” look.
“What?” Greg asked.
“Nothing,” I said. Sometimes I prefer clashing clothes to an argument.
“What? You don’t like what I’m wearing?” he asked.
“How could you possibly put those two reds together? Are you crazy?” I burst out.
“Yeah, I know it doesn’t match. I just put it on to see your reaction,” Greg said.
We went out to dinner last night. I didn’t pay much attention to Greg’s clothes until we got to the restaurant. He still had on the maroon sweatshirt, but this time his T-shirt was orange and purple. I didn’t say anything, figuring he was fooling around with me again.
We were chatting last night in bed, and I brought up the dinner clothes.
“It’s funny how you wore that orange and purple T-shirt with your sweatshirt,” I said.
“What’s funny about it?” Greg asked.
“You were doing that on purpose, right?” I said.
“What was wrong with it?” he asked.
“Orange and purple with maroon?” I said.
“Why didn’t you say something to me? I would have changed.”
“Because I thought you knew that it didn’t match.”
I’ve heard you should teach by example. And I try to. But orange, maroon, and purple? This man’s needs go far beyond my teaching capabilities.