North Country Semi-Weathering Purple is a premium quality roofing slate in various shades of burgundy with frequent inclusions of green. A percentage of these purple roof shingles will weather to tones of brown and buff over time. This semi weathering purple slate is frequently used to smooth the color transitions on multi-colored roofs. North Country Semi-Weathering Purple roof slate meets or exceeds the requirements of ASTM as an S-1 rated roofing slate.