While I am sure there are stylistic reasons for using that color, there is another common reason why you see blue-green colors in paint, especially in older industrial environments: zinc chromate/phosphate corrosion protective coatings. Zinc chromate primer is the color you see on the interior surfaces of some aircraft, to inhibit corrosion. Zinc phosphate is more of a gray in most cases, although varying paint chemistries result in a spectrum between those two, with seafoam nearly smack in the middle.

These are still available today, although the chromate version seems less popular for general use due to toxicity, especially (I assume) in the case of a fire.

I have painted quite a few bits of sheet metal with a sea-foam-ish blue-green/gray paint back in the day (30 years or so ago). I don't recall the manufacturer, but it was a zinc conversion coating in nearly exactly that seafoam color, which has probably stolen at least a few years of my life expectancy. The same company sold other paints in a sickly mustard yellow, and close to fire-engine red, all with slightly different chemistries, I assume for different base metals.