Ditto the Blue Mountains just west of Sydney. They don't look blue to me, although apparently they have a bluish haze or tint.

I guess it may be that put next to something more 'traditionally' green, these things have a blue tinge.

Colour is notoriously hard to pin down precisely in words. The Chinese (Mandarin) word 'qing' is used for the blue of the sky and the purple of distant mountains and the green of grass. The Japanese use the same character (and pronounce it aoi) for the green of traffic lights.