The Black & White mode is used when color mode is not available. The brightness of Black, Blue and Orange are 100%, 80% and 50% individually, when background color is White. When it is impossible to make brightness variation, only Black & White mode is used.
This is when specific background is given. The white is used when background is dark over K50%. The white is used for both Symbol and Logo, in case Blue & Orange are set as background. This is same when another color is set as background, but it is important to avoid making symbol and logo dime due to the brightness. Over K50% color is recommended.