One can tint UF s with titanium dioxide so that the glue blends perfectly with a blonde rod. And yes, you can lighten resorcinol considerably. The phenolic compounds gradually oxidize into the characteristic dark, reddish brown after about six months. Many epoxy formulations do not maintain good shear strength in temperatures below freezing. As the temperature goes down they get increasingly brittle until they break away from the side of the ferrule upon flexing.
Most formulations maintain good strength until flexed.
But when that happens they part due to shear forces. A few makers have been aware of this and have been using rubber cement to avoid the problem. But, rubber cement isn t very strong. However, a quick phone call to the experts at Shell revealed that there is an Epoxy formulation that has all the properties for good ferrule connections and works in the cold too. Its psi strength and bonding ability are impressive.