As part of my business, I supply a lot of Creosote treated timber, typically for Railroad use but for foundation piling as well.
In Washington State, Creosote piling is no longer permitted in Marine Waters, instead ACZA or Ammoniacal Copper Zinc Arsenate (Chemonite) is specified, if wood rather than steel.
The color of Creosote will vary.
Straight Creosote will be darker, nearly black
If in solution which means a 50/50 blend of Creosote and Petroleum, the wood will be a little more brown.