People with red–green colour blindness cannot interpret figures in research papers that use these colours. We call for all journals to provide alternative versions of figures that are more accessible to such individuals.

We searched Nature papers published in January–April 2014 that contained at least one image requiring colour discrimination: roughly three-quarters used a red–green combination. Some journals now recommend that authors recolour their figures — green and magenta, say (see, for example, B. Wong Nature Methods 8, 441; 2011).

It would be preferable if journals could include a weblink to a colour-accessible version of red–green figures, and do so retroactively for archived figures. These would also be useful for making slideshows and posters.