The blue I mixed today was a combination of phthalocyanine blue, French ultramarine, alizarin crimson, yellow ochre, cadmium red hue, and chromatic black.
Although I have been known to make life harder than it needs to be, there is actually a method to my color madness. When I was a kid playing violin, we would tune string to string, like playing a D string and an A at the same time. You could tell when they were in tune because it was like all of a sudden the sound opened up and you heard many notes played at once, rather than just two.
For me, colors work the same way. Having a complex blue creates a dynamic color with a harmony that just isn’t there in the blue straight out of the tube.