Hi Shahd,
1. This was a tricky one. I looked into this a bit because I also originally thought the same as you did, and from what I found, insulin is made quite constantly even in fasting states, but its actual release from beta cells is controlled by sensing fed states. It makes sense since it would be more effective this way since insulin is actually made in many steps (pre-proinsulin, then proinsulin, then insulin, followed by secretion). Therefore I believe this was the reason that in fasting mice, it would still show up green since you are still synthesizing the protein.
2. This is a response of your body. When the proton gradient is dissipated, there is now not enough ATP being formed, and since your body really needs ATP and FAST, its going to want to undergo even more aerobic respiration, so it makes sense for oxygen consumption to increase.
Hope that helps!
Molly