Blue Spruce turning green

I have planted many Blue spruce and even Hoopsi blue spruce and they all turned green. They are all in full sun, very fertile soil, and are irrigated.
Everything on my property grows VERY well since it is an old farm over 200 years old. To give you an idea of what the conditions are, the following have naturally taken over the landscape.
Green Ash, Red Oak, Spruce, and White Birch.

Is it the acidity of the soil? What would be the PH level to make these trees return to Blue?

Any quick help would be very appreciated.

 

Something is diminishing or obscuring the wax on the needles. Climate conditions? Algae? Do you have acidic precipitation? Maybe that has an effect, I don't know.

 

Sometimes these blue spruces turn color to green with increasing age.

 

Are these grafted plants (which are true 'Hoopsii'), or seedlings grown from cones off a 'Hoopsii' (which are not!)?

Otherwise, have the trees been sprayed with anything? Horticultural oil and some other formulations will dissolve the wax and turn the needles green.

 

These are grafts and are only a few years ago. 90cm high.

What about copper sulphate?

 

I doubt that copper sulphate would turn them green, but if the formulation included a wetting agent to make the spray stick to the foliage better, that might well do so.