Rainbow number of colour bands of a rainbow may therefore be different from the number of bands in a spectrum, especially if the droplets are particularly large or small. Therefore, the number of colours of a rainbow is variable. If, however, the word "rainbow" is used inaccurately to mean "spectrum", it is the number of main colours in the spectrum. The question of whether everyone sees seven colours in a rainbow is related to the idea of linguistic relativity. Suggestions have been made that there is universality in the way that a rainbow is perceived. However, more recent research suggests that
The Colours of Animals come into play". To make the point, Wallace lists "the cones, cowries, olives, harps, volutes, pectens, and innumerable other molluscan shells; while many of the sea-anemones, and considerable numbers of the caterpillars with warning colours, are equally beautiful." And that was not all. Wallace continued: "Still more doubtful and more opposed to reasonable probability is the statement that 'our standards of beauty are largely derived from the contemplation of the numerous examples around us, which... have been created by the æsthetic preferences of the insect world'--alluding... to the colours and structures of flowers as being due to the need of