Just a thought but this, may be a female smooth (or common newt).
Palmates tend to have less of the olive with little fingerprint marks down the sides, although do have the velvity appearance which this one appears to have (kinda used to having them in my hand to tell though)
Im afraid the guides linked to are not really very accurate. The way to be sure however is by the size at breeding (palmates are smaller) or to find a male in the breeding colours, palmates have 'gloved' back feet and a tail filament and common do have a crest - not to be confused with cresties though.
Alternatively if you look under her neck you will either see a pale bluish vein (very pale) as the skin here does not have much pigment on the palmate, the smooth with just be pale but certainly no blue sheen