Typefaces and Legibility
The choice of font can affect the legibility of text, both printed and on a screen. The character shape, text format and layout can enhance or detract from the intended meaning. In general, legibility is higher with simple "open" typefaces.
The contrast and colour of text and background also affect legibility; this can be a severe problem for people who are colour blind.
At larger print sizes, most visually impaired users benefit from having white or yellow print on a dark matt background.
However, at small print sizes, it is better to use black print on a white background.
More detailed information is provided in the guideline on typefaces.