This is the name of the color system of the numbers in Hong Kong Mark Six Lottery.

The numbers represented by the red wave are: 1.2.7.8.12.13.18.19.23.24.29.30.34.35.40.45.46 The numbers represented by the blue wave are: 3.4.9.10.14.15.20.25.26.31.36.37.41.42.47.48 The numbers represented by the green wave

The numbers are: 5.6.11.16.17.21.22.27.28.32.33.38.39.43.44.49 Mark Six Lottery is the only legal lottery in Hong Kong and one of the few legal gambling permitted by the Hong Kong government.

Hong Kong lottery was legalized in 1958.

At a legislative meeting that year, someone proposed setting up a lottery to raise funds for social welfare projects.