Blue is so beautiful. Lapis lazuli is a beautiful shade of blue. 
I love blue.  It is in fact my favorite color.
There are many different shades that mix in other colors. What is your favorite?
Light blue.  Please tell me what color needs to be added to blue in order to make lapis lazuli?
It is actually a true deep blue. It has an intense color. 
My grand daughter asked me how to make a purple color.  What color needs to be added to blue?
Purple is an intermediate on the color wheel. It takes red and blue to make. 
Thank you for your information.
Blue
Blue is one of the three primary colours of pigments in painting and traditional colour theory, as well as in the RGB colour model. It lies between violet and green on the spectrum of visible light. The eye perceives blue when observing light with a dominant wavelength between approximately 450 and 495 nanometres. Most blues contain a slight mixture of other colours; azure contains some green, while ultramarine contains some violet. The clear daytime sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering.
Bisbee Blue
Bisbee Blue or Bisbee turquoise refers to the turquoise that comes from copper mines located in the vicinity of Bisbee, Arizona. Bisbee turquoise can be found in many different shades of color and quality, from soft, low quality pale blue to the quality hard brilliant blue turquoise and almost every shade of blue in between. The highest grade of Bisbee Blue turquoise is almost lapis lazuli blue and has a brownish red spiderweb matrix. Green turquoise is also found in Bisbee, but is not usually of very high quality.