RGB vs CMYK: Why Colours Change in Print

You approved the design on screen, but the printed result looks completely different. This is one of the most common complaints in print production — and in almost every case, the cause is the same: the file was in RGB instead of CMYK.

The Core Problem

Screens display colour by mixing light (RGB: Red, Green, Blue). Printers reproduce colour by mixing ink (CMYK: Cyan, Magenta, Yellow, Black). These are fundamentally different systems, and the range of colours they can produce — the colour gamut — is not identical.

The RGB gamut is larger. Many vivid colours that exist in RGB — electric blues, neon greens, vivid oranges — simply cannot be reproduced in CMYK print. When a printer converts RGB to CMYK (which happens automatically if you submit an RGB file), those colours are approximated — usually resulting in duller, darker output.

Which Colours Are Most Affected?

• Vivid blues — often turn purple or grey in CMYK
• Bright greens — may appear more olive or muted
• Neon and fluorescent tones — cannot be reproduced at all in standard CMYK
• Skin tones — can shift to orange or pink if not managed carefully

How to Prevent Colour Shifts

Design in CMYK from the start. Set your document colour mode to CMYK in your design software before you begin. Use a CMYK colour picker to choose colours that are within the printable gamut.

If you are converting an existing RGB design, use a professional conversion in Photoshop or Illustrator — or use PrintConvert247 to convert your PDF to CMYK automatically with a proper ICC profile.