Yellow is a primary color
what is an other primary color? 
Red is a primary color in different models
what kind of models?
RGB color model
The RGB color model is an additive color model in which red, green and blue light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additive primary colors, red, green, and blue.
The main purpose of the RGB color model is for the sensing, representation, and display of images in electronic systems, such as televisions and computers, though it has also been used in conventional photography. Before the
space is not the same as the HSV, HSL or HSB color models, although their values can also be interpreted as a base color, saturation and lightness of a color. The HSL values are a polar coordinate transformation of what is technically defined RGB cube color space. LCh is still perceptually uniform.
Further, "H" and "h" are not identical, because HSL space uses as primary colors the three additive primary colors red, green, blue ("H" = 0, 120, 240°