Science supports the color-changing memories
https://www.psychologytoday.com/blog/am-i-right/201307/your-memory-isnt-what-you-think-it-is
So basically, every time you access a memory, it should not only be possible to rewrite the contents, but reassign which emotions you associate with it. This particularly makes sense in terms of adding a dose of sadness to a memory, as experiencing any great tragedy in your life will cause you to associate many related memories with a sense of profound loss, such as when a loved one passes away. Any time you remember things about that person, you'll also be conscious of the fact that you'll never see them again.
You know what noone tells you about cooking with the Dark Side? The food is really good!