So, it sounds like ordinarily his little paws would be white underneath, so I'd think that it's most likely that either...
a) as MM suggests, maybe whatever the breeder had them on had a yellow colouring to it, and he simply hasn't fully groomed this off yet...
or
b) he is padding about in his litter tray/wherever he pees, and getting a bit of wee on his feet
...is he nice and dry on his undercarriage otherwise?
(I'd only be concerned if he was constantly damp or mucky underneath)
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