[souffle]

The Standard for Golden is this :
GOLDEN, DARK ++ (Wild type agouti)
TOP COAT - Rich dark mahogany red carried approximately one third of the way down
BASE COLOUR - Dark slate grey
BELLY FUR - Ivory, with grey under colour
CRESCENTS - Pale ivory, almost white
TICKING - Heavily and evenly ticked with black, dorsal line and hair on scalp intensely shaded. Face to be swarthy with black eye rings.
CHEST BAND - Rich dark mahogany red
CHEEK FLASHES - Black
EYE COLOUR - Black
EAR COLOUR - Dark grey, almost black

and for Yellow -
YELLOW (To = male; ToTo = female)
TOP COAT - Rich dusky yellow carried well down
BASE COLOUR - Ivory yellow
BELLY FUR - Ivory
CRESCENTS - Ivory
TICKING - Heavy and even black ticking overall
CHEST BAND - Rich dusky yellow
CHEEK FLASHES - Black - not solid but concentrated ticking
EYE COLOUR - Black
EAR COLOUR - Dark grey, almost black

When seen side by side they are clearly very different especially if you look at the undercoat which is dark slate grey in a Golden but Ivory yellow in a yellow.
There are however many poor examples of golden and yellow who are carrying other genes which influence the colour showing. I'd say you would be more likely to confuse a Rust with a Golden than a Yellow with a Golden though. Young yellows are often very pale and pasty looking.
Yellows are less common and you would be best finding a breeder to get a Yellow than hoping to find one in a pet store.