Lol at combats and nylon football shirts (hence the reason DH does not buy DS clothes!)
I buy lots of separates from different shops. To be honest I am always looking and buying, but for different ages.
For example from about a year ago I was buying all sorts of separates (different coloured trousers/tops) at age 3-4 and now he is wearing them.
Now When I am out and about if I see something I like in the next size up I buy it. I also have some clothes that I really like that are two sizes bigger. (from sales mostly)
He has so many brightly coloured clothes and even brightly stitched jeans with bright tops, a lot of people comment on the colours but this is all I do. I suppose it's just thinking in advance and mixing and matching shops/seasons. Now I just have to train him not to love his Peppa Pig top!
I am doing the same for my DD, but I am not so against pink/purple as I am sludge colours.