First off this is a must have product if you have timberland shoes.
I actually spoke to timberland before buying the product just to make sure it would be ok on my shoes. They did mention how the wax would darken the leather slightly but the shoes really do need to have a protective wax to see any milage.
The wax did indeed darken slightly but not enough to be really noticeable.
Brilliant product, great to see water bead straight off my shoes.