If we look carefully at how the three systems work, we can see that one system (red) is responsible for unpleasant emotions, while two (blue and green) are responsible for pleasant emotions. When we feel anxious, angry or sad, we can be sure that our red system is working. But when we have pleasant emotions, it's not so simple.
It takes a lot of self-reflection to slowly learn to distinguish when the blue system is working and when the green system is working. Generally speaking, the emotions evoked by the blue system are closer to a pleasant excitement, exhilaration, energy, and drive, while the emotions evoked by the green system are closer to a deep sense of calm and security. But the practical distinction is not so simple.
Distinguishing them is very important from the point of view of our mental health, because the green system always promotes mental health. When the green system regulates our emotions, they are a credible indicator of what we are moving towards, whereas the blue system can deceive us: it can reinforce our substitute actions, our illusions and act as a narcotic.

This is not to say that the blue system is not necessary, but if it is the only system that becomes responsible for our psychological wellbeing, our mental health becomes vulnerable. Since the blue system is responsible for our self-worth and our self-worth depends on our success, relying solely on the blue system to experience pleasant emotions is effectively making our psychological well-being dependent on our performance. And this will inevitably have harmful consequences in the long run.
Further complicating the difficulty of distinguishing between the three systems is the fact that pleasant emotions can also occur in conjunction with the red system. The red system signals danger and encourages avoidance behaviour. When we give in to this stimulus, we can feel a very strong sense of security and relief. These feelings can easily be confused with the feeling of safety that occurs when the green system is operating. While the source of the feeling of safety that comes from the green system is being at peace with oneself and the world, the source of the feeling of safety that comes from the red system is escaping from danger. After a moment of relief, reinforcing avoidance behaviour can lead to the emergence of phobias and panic attacks in the long term.

To summarise, the danger of blue system pleasant emotions is that they make us feel good about ourselves only when we are performing well, and red system pleasant emotions are associated with reinforcing avoidance behaviour. In both cases, pleasant emotions emerge, which can easily be confused with the pleasant emotions that arise from the functioning of the green system. From this recognition, a very strict attitude could emerge, which would want to distinguish with a policing eye the precise system from which pleasant emotions arise, and radically reject interpretations and behaviours that cause pleasant emotions either in relation to good performance or avoidance. This strictness, however, is very far from self-compassion. Watching our psychic processes with such a wary eye leads to over-activity of our red system. We experience it as a constant state of danger, and our attention narrows, flooded with feelings of anxiety, sadness and anger.
The self-compassionate person knows that in the long term they have guidelines to which they align their thinking and behaviour, but in the short term they often make mistakes or compromises. 

​This is why he is gentle with himself when he chooses avoidance behaviour in a situation (red system) or tries to get out of an unpleasant state of mind by engaging in an activity that promises success (blue system). The goal is not to make sure that this never happens, but to make it less and less. Our universal human experience is that we have limits, and there are times when such a solution is the best possible solution for our possibilities. A compassionate acknowledgement of this will activate the green system, helping us to use even these less mature coping strategies as an opportunity to exercise compassion and develop our green system.
In my daily life, can I pay attention to what situations activate each of my emotion regulation systems? What are my external and internal (e.g. thoughts) threats that activate my red system? To what extent does my psychological well-being depend on my success, what emphasis does the blue system have on regulating my unpleasant emotions? When and where can I experience the peace of mind that I can just be without any specific goal struggle and without any threat, when is my green system activated?