A few years ago it was all the rage to create websites with a limited colour palette of whites and light greys. These looked great, if you were a designer looking at it on an apple cinema display, but ran into problems if viewed on a non-calibrated machine.
This style was used a lot on portfolio websites, which meant if your intended audience were designers alone, then chances are they would have all the fancy kit that would enable them to view all the minute details of your light grey on white design.
However, in today’s age, where users are consuming content on all types of devices and in all conditions, it can no longer be taken for granted that they will have their light and contrast setting just so in order to appreciate every little detail in the design.
Therefore its imperative to create high contrast on your web design to improve accessibility. The snook accessibility checker is an excellent way of checking if your design passes the WCAG accessibility standard.
But more than just complying with regulations, you should test your designs on a variety of different devices and light settings.