Planets in astrology have a meaning different from the modern astronomical understanding of what a planet is. Before the age of telescopes, the night sky was thought to consist of two very similar components: fixed stars, which remained motionless in relation to each other, and "wandering stars" (Ancient Greek: ἀστέρες πλανῆται asteres planetai), which moved relative to the fixed stars over the course of the year.
To the Greeks and the other earliest astronomers, this group comprised the five planets visible to the naked eye, and excluded the Earth. Although strictly the term "planet" applied only to those five objects, the term was latterly broadened, particularly in the Middle Ages, to include the Sun and the Moon (sometimes referred to as "Lights"), making a total of seven planets. Astrologers retain this definition today.
Hue is one of the main properties of a color, defined technically (in the CIECAM02 model), as "the degree to which a stimulus can be described as similar to or different from stimuli that are described as red, green, blue, and yellow," (the unique hues). The other main correlatives of color appearance are colorfulness, chroma, saturation, lightness, and brightness.
Usually, colors with the same hue are distinguished with adjectives referring to their lightness and/or colorfulness, such as with "light blue", "pastel blue", "vivid blue". Exceptions include brown, which is a dark orange, and pink, a light red with reduced chroma.