Grey trousers, blue blazer, predominantly white shirt (pale blue also allowed), black/green house tie, black shoes. On saturdays we had to wear a grey suit for chapel service, though we could also wear this suit on other days if we wished.
I understand the black/green house colours now have some unfortunate association with the evil House in Harry Potter!
The uniform was actually pretty smart in theory, but of course, like all schoolkids, it rapidly became very tatty and was bought at least
one size too big in order for us to "grow into it"...