'bluishness' originates from the English word 'blue,' with the suffix '-ish' indicating a slight degree, and '-ness' forming a noun to denote a state or quality.

'bluish' changed from the Old English word 'blēo,' meaning 'color or hue,' and eventually became the modern English word 'blue.'

Initially, it meant 'a color or hue,' but over time it evolved into its current meaning of 'the quality of being somewhat blue.'