This is definitely backwards (me saying anything at all), but I'll try to pick out why this works so well for me:
- blue kilt echoes the river and sky, and is repeated in the tattersal shirt, scarf, and also the saltire!
- red hose is picked up again in the tie and faces but also in the reddish browns of dormant winter vegetation.
- greenish tweed with buttons that combine with wife's coat
- general tattersal and plaid pattern echoes across the whole

So the general schema fits the landscape very nicely and seems to be a practical adaptation to it. In a different setting, the attire might still bring memories of such a landscape, which is part of the charm of Highland wear, isn't it?

Lovely picture! Don't change a thing!