First use lake blue and a proper amount of black. After the two colors are mixed, adding a proper amount of white will basically have the effect of haze and blue. Among pigments, lake blue is the most easy to modulate haze blue effect, and other blues are not easy to modulate into standard haze blue. If you don't have lake blue on hand, you can use ordinary blue with appropriate amount of gray, and then use appropriate amount of white to modulate, or you can have haze blue effect.