No Mommy - that's not cool

So, this evening we (husband, kids & I) were getting ready for our evening walk. I was handing out the battery-operated light sticks (to make us all a little more visible), and handed Liam a green one. When he saw me putting on the blue one, he protested and said he didn't want the green one.

I said "You don't want the green one?"

His response - "No Mommy, it's not cool"

This from a (barely) four-year-old. I think I'm in trouble...