A method and an arrangement for improving the digital-signal-generated grayscale resolution of a monochrome visual display unit (3) to which the digital signals from an image source (1) can be supplied over n-bit wide RGB channels (2). Measures are proposed that make it possible to display distinguishable grayscale gradations on the visual display unit (3) regardless of whether a grayscale signal (6 10) or RGB color signals (12, 13, 14) are transmitted to the visual display unit (3).