I watched the sky as it changed over sunset towards darkness but particularly loved the colour behind the lower treescape. I have found my camera does not always capture the exact colours so have to manipulate the edit until I feel it is real.
Personally - sitting in a seat with a bad back is not always the right thing to do. You are supposed to keep moving. However, I don't care - it doesn't hurt sitting. I'm getting old and do not have to do what is supposed to be best!
Sitting down when you have a bad back works for me, with a hot water botttle on it too.
I say do what makes you feel best and if sitting makes you feel best then do it