A red that's closer to yellow would be warm, but not a blue.
The same rule applies. The blue in the OP is devoid of any yellow, so, when I look at it, it's completely cool, and clear.
Yellow (and red and orange, etc) add warmth. It doesn't mean you can't get cool yellows, oranges and reds, but those are the colours that add warmth.
This is a clear, cool blue to me.