Pigments, like people, display a great variety of personalities. Apparently some tempera painters eschew Thalo blue, given the way it overpowers all other colors in admixtures. When I am adding it to another color, I employ the tip of a toothpick to bring in minute quantities at a time. Otherwise, the whole world quickly turns blue.
On the other hand, the shy Potter's Pink whispers its transparent way onto the painting. In the realm of egg tempera painting, there is a place for such gentle colors amid the cacophony of louder pigment voices.