architecture Austria blue sky city classic copper cupola dome green roof hill leaves mountain roof roofs salzburg sky trees verdigris windows wood arch arched architectural art glass artistic artistry cames christian circle clear colored coloured contrasts craftsmanship cream dark Designs diamonds external framed glass lead light lines outside patterned patterns shapes stained glass symbolic textured window arches art-glass building color coloration colors colour colours contrast decorative design designed frame lighting perspectives reflections rippled shade shades-of-colour shaped stone-wall textures wall