A HI-TECH timepiece on top of Asia's tallest building is intended to change the time-reading methods of the world, but so far it has not stirred Hong Kong at all. The coloured lights which crown Central Plaza are supposed to represent the newest way of telling the time. ''Lightime'' inventor Martin Tam Tin-fong hopes colour-coded time will be the successor to digital clocks. ''This time piece is aimed at changing the way future generations tell the time,'' said Mr Tam, the managing director of construction at Sun Hung Kai Property. He said civilisation had progressed from reading sun dials and hour glasses to clocks and digital time pieces. ''Now, we want future generations to read the time in colour,'' he said. ''We want to revolutionise more than the Hong Kong skyline.'' However, Mr Tam admitted that he had received little public feedback or interest about Lightime since its launch two months ago. ''I'm not sure what Hong Kong thinks,'' he said. Mr Tam said he had been reluctant to publicise himself as the inventor of Lightime, so that he could gauge people's unguarded opinion. ''I don't want people ringing me saying it's a great idea just because they're my friend. I intended Lightime to be a service to Hong Kong and I want people's honest response.'' But the population has been quiet about Lightime and Mr Tam is still unsure of its success. The rectangular column of lights on top of Central Plaza indicate the time by changing colour and blinking six times on the quarter hour. Four neon bands, each representing 15 minutes, change colour until they are all the same colour of the new hour. Each hour is represented by a different colour. The timepiece is nocturnal, only working 30 minutes before sunset and half an hour after sunrise. Mr Tam admitted it could be confusing for some. ''My wife thinks it's stupid but most of my friends think it's great,'' he said. Its accuracy is checked daily, but there is little scope for error because it is linked to the Royal Observatory's atomic clock. Two million cards - about the size of a credit card - have been produced to explain how to read the colours of Lightime. The cards were handed out at Lightime's launch and also distributed through schools. ''It is the children I am most eager to teach. I dream of a day when the children's hour on TV will show a colour-coded time box in the corner instead of a Rolex clock,'' Mr Tam said. ''I have this romantic vision that my great grandson will tell his girlfriend to meet him at gold o'clock under the Waterloo Bridge.'' But he wants Lightime to transcend the boundaries of this territory. ''Perhaps Sydney Harbour will have one by the 2000 Olympics,'' he said. However, Mr Tam said that Central Plaza owned the patent to Lightime so other countries could only have the futuristic timepiece if they paid the royalties.