@gotta, Well, like I said, I think the correct teaching that we, as parents can and should try to convey to a child is neither ‘rules are rules, switch off your brain and shut up’ nor ‘no rule should apply to you, my precious snowflake’, but a sensible compromise between these two extremes. I don’t want a spoilt brat but I also don’t want an obedient, brainless zombie.
Life is full of stuff we may not like and/or find incredibly useless or counterproductive. It’s important to choose your battles. It’s important to appreciate that you won’t always get what you want. But it’s also important not to switch off your brain and passively accept that ‘rules are rules’.
Wrt to the grey trousers, my gripe is not that I cannot buy them, but that checking for the right shade of grey is a sign of the school having the wrong priorities. Or, shall I say, I am lucky enough that I can buy them without batting an eyelid, but not all families are so lucky: shocking horror for some people on the forum, but there exist people poorer than us and/or with multiple kids, who wouldn’t mind saving a few quids on school uniforms. Why shouldn’t Johnnie be able to use Billie’s grey trousers, just because they went to different schools or the uniform has changed, and Billie’s grey is now the wrong grey?
Not to mention @giles’ example of other situations where the school uniform is simply inadequate for the weather conditions (why freeze in the winter or boil in the summer?).