The photos and your description do not match any common spruce diseases. (I will give you a ink to that site). You say you planted the trees. Did you prepare the planting hole by loosening the soil and mixing in good compost half and half. Sandy soil does not have water retention capabilities and the trees look like they are not getting enough moisture. Sitting out there in the open on sand exposed to wind will dry out the needles very quickly. Also, spruce like acidic soil (sand is usually neutral) so the addition of fertilizer for acid loving plants would be helpful. These young trees also need to have water provided to them. We recommend that newly planted young trees have a hose laid at the base and water trickled for 30 minutes or so every other day until they are well established. I think this is wrong tree in the wrong place but if they insist on spruce, it will take work on their part and yours. Scotch pine, mugo pine and junipers are recommended for sandy soil.  http://apps.extension.umn.edu/garden/diagnose/plant/evergreen/spruce/needlesdiscolored.html    https://extension.umn.edu/planting-and-growing-guides/watering-newly-planted-trees-and-shrubs