What is your favourite colour? Mine is purple. It is an intermediate colour between blue and red.
Mine is blue!  I have a lot of clothes that are blue!
Blue is good. It is one of the primary colours.
What do you mean primary?
Primary colours are any of a group of colours from which all other colours can be obtained by mixing.
Oh.  I think I sort of remember that from school.  What did the intermediate mean that you stated before?
It means on the traditional colour wheel used by painters, it is the inbetween colour between red and blue.
I see.  So the color wheel consists of primary colors and all the intermediate colors are mixed up primary colors, right?
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.
He included indigo, the hue between blue and violet, as one of the separate colours, though today it is usually considered a hue of blue.
In painting and traditional colour theory, blue is one of the three primary colours of pigments (red, yellow, blue), which can be mixed to form a wide gamut of colours. Red and blue mixed together form violet, blue and yellow together form green. Mixing all three primary colours together produces a dark grey. From the Renaissance onwards, painters used