Hi Amber, not a brilliant explanation but liath is always used for hair also always used for smoke. Glas is always used for the grey of the sea. Hope this helps a bit.
That's very helpful, thank you!!
I know that there is some differences between how we understand green/blue/grey in english and the gaelic gorm/liath/glas/uaine, but could someone explain why 'glas' is not appropriate here?