In English, we often use the adjective light before another colour to express a whiter shade of hue. For example, light blue, light green, light brown, etc. The term pale is used in a similar way, e.g.; pale grey, pale yellow, and pale red.
Etymonline dates this usage of light:
light (adj.2) (see light (n.)). Meaning "pale-hued" is from 1540s.
and for pale early 1300s
pale (adj.) early 14c., from Old French paile "pale, light-colored" (12c., Modern French pâle), from Latin pallidus "pale, pallid, wan, colorless," from pallere "be pale, grow pale,"
If we look at names for “light blue”, only azure predates Early Modern English
- azure early 14c., from Old French azur, asur, a color name...
- sky blue is said to have first appeared in print in 1704
A Collection of Voyages and Travels (London: Awnsham and John Churchill, 1704), vol. 2, p. 322, where John Nieuhoff describes certain flowers: "they are of a lovely sky blue colour, and yellow in the middle" Wikipedia
- cyan (originally called cyan-blue) meaning ‘light blue’ is dated 1879
To illustrate my point more clearly, here is a Google Ngram set at British English, which suggests that the combination, light + name of colour, began from mid 17th century.
- How did Middle and Early Modern English speakers say that a colour was light?
- Did they place term white before a colour; e.g. whit blewe (white blue)?
- What does whyte russet mean? Is it a ‘pale reddish-brown’?