They say beauty is in the eye of the beholder. As designers, we need to remember that the same is true of color and all visual abilities. It’s estimated that 4.5% of the global population experience color blindness (that’s 1 in 12 men and 1 in 200 women), 4% suffer from low vision (1 in 30 people), and 0.6% are blind (1 in 188 people). It’s easy to forget that we’re designing for this group of users since most designers don’t experience such problems.
article available here: http://www.uxbooth.com/articles/accessibility-visual-design/