[enobrev]

I had initially thought the same about different screens but then I saw it change on my phone.

The first time I passed by my friend's post with the photo on my facebook feed, it was white and gold. I ignored it and scrolled on. A few minutes later while scrolling back up to the top, that same exact picture (same post) was blue and black.

I've seen it switch a couple times since on my phone (nexus 4). Although on my desktop it's always white and gold.

[zamalek]

Did you move between different locations? The difference could come down to being outside vs. being inside - or at least eye-shot of sunlight.

[enobrev]

Didn't move at all - besides my finger as I scrolled through my feed. Ambient light was the same - pretty much everything was the same.