Ryan, I spent an hour at Home Depot with a HD representative going to every location where tubing was sold and we never found a grey version of the exact tubing. I am going to a lawn mower shop tomorrow and see if a gas weed trimmer fuel line is the correct size. I have windshield washer tubing, but it is thick walled with no give to it. There has to be some give so the glass can flatten the tubing a bit when the bolts are installed.