This paper explores the transformation of color gamuts in digital control of color television monitors, particularly focusing on the RGB monitor gamut. It introduces two alternative models of the RGB monitor gamut: the hexcone model and the triangle model, both based on perceptual variables such as hue (H), saturation (S), and value (V) or brightness (I). The paper provides algorithms for transforming between these models and the traditional colorcube model, which represents colors as vectors in a 3-dimensional space. The hexcone model captures the artistic notions of hue, saturation, and value, while the triangle model includes hue, saturation, and brightness. The paper also discusses the computational efficiency of these transforms, noting that the hexcone model is faster and more suitable for real-time applications, while the triangle model is useful for more complex manipulations like NISC space adjustments. Guidelines for choosing between the models are provided, and psychophysical corrections are described within the context of NTSC standards. The paper concludes with examples and references to support the theoretical developments.This paper explores the transformation of color gamuts in digital control of color television monitors, particularly focusing on the RGB monitor gamut. It introduces two alternative models of the RGB monitor gamut: the hexcone model and the triangle model, both based on perceptual variables such as hue (H), saturation (S), and value (V) or brightness (I). The paper provides algorithms for transforming between these models and the traditional colorcube model, which represents colors as vectors in a 3-dimensional space. The hexcone model captures the artistic notions of hue, saturation, and value, while the triangle model includes hue, saturation, and brightness. The paper also discusses the computational efficiency of these transforms, noting that the hexcone model is faster and more suitable for real-time applications, while the triangle model is useful for more complex manipulations like NISC space adjustments. Guidelines for choosing between the models are provided, and psychophysical corrections are described within the context of NTSC standards. The paper concludes with examples and references to support the theoretical developments.