The blue house

I was very tired today, and thought it was because of all the travelling for the last couple of days. So in the afternoon I went for a walk, trying to perk me up. During my walk I saw this blue house, and it was the most colour I saw, because the sky was grey, and everything looked rather drained. In the evening I realised my tiredness wasn't normal, I was indeed coming down with some illness. I had a terrible headache, pain in all my limbs and felt as if I had fever (although I didn't check).