State the term- Hue

Hue  is the dominant spectral colour (rainbow) and is related to the wavelength of light. In Munsell system there are five principal hues; red (R), yellow (Y), green (G), blue (B), and purple (P) and five intermediate hues representing midpoints of each pai r of principal hues. The intermediate hues are yellow-red (YR), green-yellow (GY), blue-green (BG), purple-blue (PB), and red-purple (RP). Thusa total of 10 hue names each with four numerical segmentation i.e., 2.5, 5,  7.5, and 10 are used to describe the notation, e.g.,  2.5Y, 5Y, 7.5Y and 10Y etc. are the possible notations  for principal hues and 2.5YR, 5YR, 7.5YR and 10YR etc. represent the same  for intermediate hues.