Is specifying link colours a violation against WCAG's Success Criterion 1.4.8?

Question

The text of the WCAG's Success Criterion 1.4.8 page says:

Success Criterion 1.4.8 Visual Presentation (Level AAA): For the visual presentation of blocks of text, a mechanism is available to achieve the following:

Foreground and background colors can be selected by the user.

One may choose from five different given techniques to satisfy this part of the criterion: C23, C25, G156, G148, or G175. The latter, G175, states that a colour-picking tool must be provided.

All the others techniques except for G156, however, explicitly mention that no background and no foreground colour must be specified for the texts, at least not for the main content's texts.

However, is specifying colours for the links in those texts (supposing no colour-picking tool is provided on the page) a violation against Success Criterion 1.4.8, or is it satisfactory due to the fact most modern browsers are compatible with the demands of the technique G156, since they let the users change the page's colours?

If so, then is it acceptable to specify background and foreground colours also for the main content's text, given browsers let the users change these specifications?

Answer 1

Technique G156 states:

In order to meet this success criteria, the Web author would design the page so that it works with browsers that have these controls, and the author does not override these controls.

As long as your site runs on modern browsers and you're not doing anything to override the browser's ability to change background, foreground, and link colors, you would be meeting this criteria.

In the "Tests" section of Technique G156, run through the test procedure and make sure the colors change on your site when you change them using the browser controls. Here's a guide for how to change colors in various browsers: http://www.bbc.co.uk/accessibility/guides/change_colours/browser/