Most countries set their visa laws based on the passport of the visitor rather than the permanent resident/work permit status of the passport holder. Singapore has had traditionally high stay over rates by Indian and Chinese passport holders and so are very particular on asking for visa prior to landing. Several years ago they had allowed Indian passport holders with Australian permanent residence to enter for 72 hours without obtaining a visa. They abruptly changed the rules and a friend of mine travelling from Australia to India with a planned stopover in Singapore had to spend the night at the airport. The probability of an Australian PR to stay back in Singapore is zero, but they set the rules based on the country of passport not PR status.
So in short, always check prior to travelling to any country on a developing country passport.