The sun had already set at that point and the pinkness was in the wrong spot for it to be a sunset, it was more in the middle of the sky, looking back on it it probably was the aurora but because of all the clouds it looked like this strange pink haze in the middle of the sky.
(...with the absolute caveat that it could be aurora, especially as there was aurora around... even if I
still didn't see it...)
That could always be signs of the sunset that you'd still be seeing if you were stood on a high (cloud-high) tower. The red-tinged light of sunset scraping over the 'over-the-horizon' horizon and illuminating some isolated cloud/high-level-haze in absolutely whatever part of the sky it happens to be. All it needs to do is not be blocked off by yet more sunward clouds.
The old "Red sky at night, (sailor/famer)'s delight, red sky in the morning (their) warning" relies on this, even more than the horizon-adjacent sky itself going red around the setting/rising Sun[1]. Clear skies over the westward/eastward horizons revealing the absence of clouds that might arrive or had been (with the correct type of prevailing weather system, of course). But also needs clouds up (mostly) in the eastward/westward skies to pick up on this diffused light (if you hadn't had clouds, you are more than likely probably now due them, and if you already had clouds then their now being lit up red is a good sign that there's no more to come. Certainly consistently enough to give the right sort of hints enough of the time for fishing or farming communities to take head of. (Also, it rhymes, so it must be true!)