I've always just thought of icicles as clear. Apparently there is a lot of pollution on the roof top, if it produces yellow icicles. The Sharp shadows cast by the icicles onto my house, created 'shadow-cicles'. In Apalachin, I happened to notice this plant that was still green and hardy. Well no wonder, You'd keep your color too if you were encased in ice. So there you have it. Green-cicles too!