That appears to be winter desiccation not blight - essentially insufficient water to keep the leaves hydrated. Desiccation is a common problem with conifers and broadleaf evergreens in the Denver area because, unlike deciduous plants, evergreens continue to transpire through the winter and the plants are unable to replace water lost through transpiration. Lack of winter precipitation, intense sunlight at elevation with the sun low in the sky, drying winter winds, and inability to uptake existing moisture because the ground is frozen all contribute to desiccation.
The only thing you can do is initially site evergreens out of south & western exposures and winter water when the ground isn't frozen.
Watch your boxwood and if enough of it buds out, prune away the dead. Boxwoods have the ability to survive hard pruning so over time the plant may fill back in. Next winter, winter water if we don't get precipitation. Here's some information: http://planttalk.colostate.edu/topics/trees-shrubs-vines/1706-fall-winter-watering/
Thanks for getting back with your advice so quickly.