While this picture is a piece of artwork it made me think what your organization can look like if you view Lean only as a set of tools. Losing the perspective of your system can easily lead to creation of complex and unusable solutions like this traffic light.
When I look at this traffic light tree, I picture one team adding one of the lights, then another team comes along and adds a light for their use, then a management team adds a third light to summarize what the other two teams lights represent, then more teams continue to add their light for their own use, and so forth. While a new light may be a solution for each group individually, the net result is a confusing and unusable tool for the system.
When you set out to improve things, think about the needs and impacts to the system. Take the time consider all options before acting. It is not true improvement if you optimize one area but the result is sub-optimizing another.
Keep on improving!