I contacted DRV, and yes, it's true...they no longer use colored caulk. They now use clear silicone.
However, I was able to find out that they previously used Geocel 2300 Tripolymer Sealant. I'm not sure of the color, but I beleive it's Bronze, but I'm still investigating.
The manufacturer web site is
http://www.geocelusa.com/php/oic/pro...b_product_id=7
The distributer (in Elkhart) website is
www.geoceltransportationproducts.com
There's also an informative video about the product on Facebook
http://www.facebook.com/video/video....04852536207683