Hi, As a newcomer to JabRef and this site I've been (trying) to read the FAQ pages. Unfortunately the combination of text colour and background colour makes most of the sections very difficult to read. I'm colour blind (along with approximately 8% of the male population) and the section "JabRef and Mac OS X" IS unreadable to my eyes.
For general information on creating accessible web pages see https://www.w3.org/WAI/gettingstarted/tips/designing
For detailed advice on how to ensure sufficient contrast see section 1.4.3 of https://www.w3.org/WAI/WCAG20/quickref/#qr-visual-audio-contrast-contrast
Please remove the coloured backgrounds.