For the moss example I only used the grey channel, because dealing with all three channels can get really complex, as colours always consist of all three channels, but have only one brightness.

• 为莫斯例如我只使用了灰色渠道，因为处理所有三个渠道可以得到真正复杂的，因为颜色总是包括所有三个渠道，但只有一个亮度。