翻译一句话（需高手指点，BS机翻!）

黑白用gray scale吧。

全句可翻译作：
Bills are mainly printed in gray scale, or color printed with preprints.

The black and white bill primarily, or has the advance print colored bill

黑白账单为主、或带有预印的彩色账单；
Black-and-white bill, or has colored bill preprinted for the main fact;