Unusual that the Scottish Gaelic word for "light blue" is the same as the Irish word for "grey" - see also "glas" , which is "grey" here, but "green" in Irish!
LIATH also can mean "grey" in Scottish Gaelic, I think, e.g. when referring to hair. Colour words in Gaelic don't translate one-on-one to colour words in English - I hope the course will take account of this.
Could one compare light blue and grey to similar colours in the sky? The perception of colours sometimes differs from language to language. cf. black eye = blaues (blue) eye in German