I grew up near the Irish Sea, which is mostly grey, but the Ligurian Sea is genuinely blue.
As most of you know, I don't approve of using lots of adjectives, but you're all going back to school and you're going to need some interesting words, so I thought I'd help you out with some alternative words for 'blue'.
A good one to start with is 'azure'. For historic reasons we only use this word for beautiful blues. You tend not to get an azure bruise - or wear azure sports kit( except in Italy where 'azurro' just means' blue'). Originally it came from the Persian word for a gorgeous blue stone called lapis lazuli, which looks like this:
What about the sky in that picture? To me it's forget-me-not blue - but to you it might be the blue of a flag, or a football shirt - or a street sign.
Here are some other blues:
Ultramarine means 'beyond the sea' . you know why? Because it was a pigment made from grinding up lapis lazuli, which came from beyond the sea.
Best wishes to you all for the new term