Ah yes, fashion victim boys. I have just such a one myself.
Cheer up, justtheone, it could be worse, My ds at 2.5 insisted on wearing his older sister's Barbie pyjama top to nursery every day. He also had a thing for pink pants, with either flowers or bows on. This phase lasted about six months, before the scales fell from his eyes and he realised this was not what the tough guys were wearing. Then he moved on to a Spiderman/combat clothes obsession.
Now at 4.5 he's still extremely particular. He'll come out of his room wailing 'I haven't got any trousers.' When I go to look and point out that there are at least 6 pairs in the cupboard, he'll say: 'Yes, but none of those trousers suit me.' Alternatively, he'll moan that none of the socks in his drawer match whatever t-shirt he wants to wear.
Why fight it? It sounds as if he's prepared to accept that the jeans need washing from time-to-time, which is a great step forward. Personally I tend to draw the line at daytime clothes being worn in bed on the grounds that it dirties the sheets. So far ds has always been prepared to accept that, and I haven't had to fight it.
Make life easier by not buying expensive clothes; ours are mostly hand-me-downs from a friend's son topped up by visits to Oxfam. I'm very reluctant to buy him full-price stuff, as he might take against it. If I've paid 99p for something, I don't really mind whether he wears it or not.
And don't make the mistake of signing him up for a school with no uniform...