 After the initial rush to mass-build flats in the 1960s however, varying façades began to appear in subsequent decades, initially only through subtle variations such as coloured tiles, but which became full-scaled multi-coloured paintwork complete with bright motifs from the 1990s.After several elaborate designs, some of which subsequently presented logistical headaches during maintenance, more subdued and contemporary designs began to emerge from the 2000s.Up to 80% of Singapore's population live in HDB flats.