Yellow is the part of knowledge in the world that you are knowledgeable in.
Black is the part of things which you know exist but you don’t know how it works.
White is the part which you don’t even know exists in the world.
A perfectionist wants to know it all. Take action on the things you are knowledgeable, even if you learn new things daily you can never make the whole circle yellow. It’s better to start taking action with the knowledge you have rather than waiting until you don’t have this precious time anymore!