Background and foreground color of Kanjis are decided at random, except for the “rare” cases.
There can be rare cases that either background or foreground, or both in the super rare case,
the color is selected from red, white or black.
The occurrence rate of those colors are as follows;
- Red: 10 %
- White 1%
- Black 0.1%
- Common (Other than those above) 88.9%
“Rarity” is defined as follows;
- bR : Background is Red
- bW: Background is White
- bB: Background is Black
- fR: Foreground is Red
- fW: Foreground is White
- fB: Foreground is Black
And combination of them will be moreover super rare, for example,
bRfB (background:Red + foreground:Black): 10% x 0.1 % = 0.01%
Possible combination can be as follows;
| Common | bR | bW | bB | |
|---|---|---|---|---|
| Common |  78.022% |  9.89% |  0.899% |  0.089% |
| fR |  9.89% | – |  0.1% |  0.01% |
| fW |  0.899% |  0.1% | – |  0.001% |
| fB |  0.089% |  0.01% |  0.001% | – |
Since the program eliminates the case that the Kanji word is invisible, i.e. background and foreground is the same color, there cannot be those cases.
(To be honest, I’m considering that it can be exciting that there are some “invisible” ones with super rare rarity,,,,= super high value, though)
And the virtu of the Kanji varies inversely of this rarity.