That same thing always happens to me with blueberry muffin. I tried everything I could think of it and it would still change color on me. I finally ordered a new bottle of fo cause I was about out and the new bottle isn't doing that so far. I got morphing colors with chips, blocks, and liquids. It even changed on me in paraffin too. I don't have any advice, I just feel your pain! Hopefully someone can help ya!