The original chinese dice are small dice with the 2,3,5,6 black-colored, the 4 red colored, |
and the 1 either large and red-colored, or just an impression without color.
The explanation for the red one and 4 is the following (according to everything2.com):
Once upon a time, when Emperor Hsuan-tsung of the Tang dynasty was playing dice with his concubine Yang Kuei-Fei, he needed three fours to win the game.
He threw the dice, and the first die settled immediately on a ‘four.’ Excitedly, the Emperor cheered “Four! Four!”, and both of the remaining dice, obediently, settled on ‘four‘.
Naturally, the Emperor felt rather smug about this display of imperial fiat, and a eunuch waiting on the Emperor suggested that this phenomenal fortune should be marked by something.
Thus, the Emperor decreed that in all future the ‘four’ on dice should be colored red and so it came to be.
In China red is considered to be a very auspicious colour, and the symbol of luck and good fortune.
Traditionally the ‘one’ on Chinese dice are also coloured red as the 'one' is the ace and often the highest throw in Chinese dice games.
Nowadays, however, the one is usually left blank, as seen on Mah Jongg dice, hollowed out to preserve the balance of the die.
Furthermore, the pips of the 2 are placed horizontally and not diagonally (as usual).
Modern chinese dice are still the same but often larger and both dice and pips come in many colors.
The Gambling Games Of The Chinese In America, by Stewart Culin, 1891
Chinese games with dice, by Stewart Culin, 1889
You can see more chinese dice in: MAHJONG DICE and BELANKAI SPINNERS.