I understand the rules in Cambridge Dictionary grammar tutorial, like any + plural countable noun
and
A: I don’t think I’ve ever seen you paint such a beautiful picture before. Gosh! Did you choose the colours?
B: We could choose any colours we wanted.
and any + uncountable noun
Do I need to get any petrol?
I am not sure which rule should I use with "difference"
Ngram Viewer shows both are common.
An ELL post uses it as an uncountable noun
I'd like to know if there's any difference in meaning between ...
Another ELL post goes with the rule of plural countable noun.
the differences between ...